1. The document analyzes tool wear and inclusion behavior during turning of a calcium-treated steel using coated carbide tools.
2. It finds that inclusions like MnS, mixed sulphides (Mn,Ca)S, and duplex calcium aluminates deform significantly in the flow zone near the tool. MnS deforms the most while mixed sulphides deform less.
3. The behavior and deformation of inclusions in the flow zone influences tool wear and formation of protective layers on the tool surface. Certain inclusions like mixed sulphides are more likely to form protective layers due to their deformation characteristics.
Wear performance of ceramic cutting tool materials when cutting steelLepuufu
The document summarizes the results of a study that tested the wear performance of various ceramic cutting tool materials when cutting steel. It found that alumina-based materials like alumina-zirconia (F) and alumina in submicron grain toughened by zirconia (G), as well as mixed-based alumina (Z), exhibited the best wear resistance when cutting steel at high speeds up to 11 m/s. These materials demonstrated tool lives between 180-300 seconds at the highest speed tested. In contrast, silicon nitride (S), sintered carbide (C), cubic boron nitride (B), and alumina reinforced with silicon carbide whiskers (W) showed
Cutting of hardened steel is a topic of high interest for toda 's industrial production and scientific research.
Machine parts consisting of hardened steel are high peiormance components which are often loaded
near their physical limits. The functional behavior of machined parts is decisively influenced by the fine
finishing process which represents the last step in the process chain and can as well be undertaken by
cutting as grinding. An overview of the mechanisms of chip removal in hard cutting and the thermomechanical
influence of the work area is presented. Furthermore, several models of chip removal in hard
turning are introduced and discussed summarizing the metallurgical fundamentals and giving an overview
on stress and temperature distributions in the work area. Boundary conditions for hard cutting as e.g.
machine tools, cutting materials and others are subject to discussion to determine the achievable
workpiece quality and economic efficiency of hard cutting processes in comparison with grinding.
Study of Pitting Corrosion Behavior of FSW weldments of AA6101- T6 Aluminium ...IJERA Editor
Friction Stir Welding (FSW) is a promising solid state joining process widely used generally for Al alloys,
especially in aerospace, marine and automobile applications. In present work, the microstructure and corrosion
behavior of friction stir welded AA6101 T6 Al alloy is studied. The friction stir welding was carried using
vertical milling machine with different tool rotational speeds and welding speeds. The microstructure at weld
nugget or stir zone (SN), thermo-mechanically affected zone (TMAZ), heat affected zone (HAZ) and base metal
were observed using optical microscopy. The corrosion tests of base alloy and welded joints were carried out in
3.5% NaCl solution at temperature of 30º C. Corrosion rate and emf were determined using cyclic polarization
measurement.
Chip flow and notch wear mechanisms during the machining of high austenitic s...Lepuufu
This document discusses notch wear mechanisms during the machining of high austenitic stainless steels. Special step-turning tests were conducted on four stainless steel alloys to study the degree of work hardening ahead of the tool and the side flow of work material at the depth of cut line. Microhardness measurements and SEM analysis showed severe localized shear and chip side flow interacting strongly with the tool, leading to notch wear initiation. Notch wear was found to be most sensitive to cutting parameters for the alloy with the highest nickel content, and increased with feed and depth of cut. Hardness was highest in the side flow region, indicating work hardening affects notch wear progression.
Wear performance of ceramic cutting tool materials when cutting steelLepuufu
The document summarizes the results of a study that tested the wear performance of various ceramic cutting tool materials when cutting steel. It found that alumina-based materials like alumina-zirconia (F) and alumina in submicron grain toughened by zirconia (G), as well as mixed-based alumina (Z), exhibited the best wear resistance when cutting steel at high speeds up to 11 m/s. These materials demonstrated tool lives between 180-300 seconds at the highest speed tested. In contrast, silicon nitride (S), sintered carbide (C), cubic boron nitride (B), and alumina reinforced with silicon carbide whiskers (W) showed
Cutting of hardened steel is a topic of high interest for toda 's industrial production and scientific research.
Machine parts consisting of hardened steel are high peiormance components which are often loaded
near their physical limits. The functional behavior of machined parts is decisively influenced by the fine
finishing process which represents the last step in the process chain and can as well be undertaken by
cutting as grinding. An overview of the mechanisms of chip removal in hard cutting and the thermomechanical
influence of the work area is presented. Furthermore, several models of chip removal in hard
turning are introduced and discussed summarizing the metallurgical fundamentals and giving an overview
on stress and temperature distributions in the work area. Boundary conditions for hard cutting as e.g.
machine tools, cutting materials and others are subject to discussion to determine the achievable
workpiece quality and economic efficiency of hard cutting processes in comparison with grinding.
Study of Pitting Corrosion Behavior of FSW weldments of AA6101- T6 Aluminium ...IJERA Editor
Friction Stir Welding (FSW) is a promising solid state joining process widely used generally for Al alloys,
especially in aerospace, marine and automobile applications. In present work, the microstructure and corrosion
behavior of friction stir welded AA6101 T6 Al alloy is studied. The friction stir welding was carried using
vertical milling machine with different tool rotational speeds and welding speeds. The microstructure at weld
nugget or stir zone (SN), thermo-mechanically affected zone (TMAZ), heat affected zone (HAZ) and base metal
were observed using optical microscopy. The corrosion tests of base alloy and welded joints were carried out in
3.5% NaCl solution at temperature of 30º C. Corrosion rate and emf were determined using cyclic polarization
measurement.
Chip flow and notch wear mechanisms during the machining of high austenitic s...Lepuufu
This document discusses notch wear mechanisms during the machining of high austenitic stainless steels. Special step-turning tests were conducted on four stainless steel alloys to study the degree of work hardening ahead of the tool and the side flow of work material at the depth of cut line. Microhardness measurements and SEM analysis showed severe localized shear and chip side flow interacting strongly with the tool, leading to notch wear initiation. Notch wear was found to be most sensitive to cutting parameters for the alloy with the highest nickel content, and increased with feed and depth of cut. Hardness was highest in the side flow region, indicating work hardening affects notch wear progression.
This document reviews additive manufacturing research on cermets. Several powder-based AM processes have been used to produce cermets, including selective laser sintering/melting, laser engineering net shaping, direct laser deposition, and binder jet 3D printing. Research has focused on optimizing process parameters to produce dense, crack-free cermet components and evaluating properties like density and hardness. Key findings include that SLS/SLM of WC-Co is most widely studied and parameters like laser power, scan speed, layer thickness influence microstructure and properties of final parts.
This document summarizes a study on the formability of various Indian stainless steel sheets formed under different stress conditions. Experimental work was conducted to determine the forming limit diagrams, microstructures, tensile properties, crystallographic textures and void characteristics of SS301, SS304, SS409M, SS430 and SSLN1 steel grades. Micrographs showed SS304 has a mixed grain structure while SS301 has coarse grains with carbides. Forming limit diagrams were plotted from strain measurements. Texture analysis was performed using X-ray diffraction. Void size, shape and spacing were analyzed from SEM images. Properties including yield strength, elongation and strain hardening exponent were calculated and correlated with formability.
The document summarizes research characterizing the forming behavior of aluminum alloy AA5754 at elevated temperatures. Key findings from tensile and forming tests are:
1) Yield strength, strain hardening exponent, and flow stress decrease with increasing temperature, while elongation increases.
2) Warm forming from 100-250°C improves formability over room temperature forming.
3) A test setup was developed to evaluate forming limits at elevated temperatures up to 250°C.
Mechanism of Fracture in Friction Stir Processed Aluminium AlloyDr. Amarjeet Singh
Aluminium alloys are used for important
applications in reducing the weight of the component and
structure particularly associated with transport, marine,
and aerospace fields. Grain refinement by scandium (Sc)
addition can eliminate the casting defects and increase the
resistance to hot tearing for high strength aluminium alloys.
FSP for cast aluminium alloys have been focused and it has
great advantages including solid state microstructural
evolution, altering mechanical properties by optimizing
process parameters. These parameters are tool rotational
speeds (720, and 1000 rpm), traverse speeds (80, and 70
mm/min), and axial compressive force at 15 kN, etc. The
mechanical properties had been evaluated on FSPed
aluminium alloy with different microstructural conditions.
Fracture properties of aluminium alloys are very important
for industrial applications. Tensile and fracture toughness
properties were correlated to microstructural and
fractographic features of the aluminium alloys need to
explore their essential failure mechanisms.
The document summarizes a study that investigated the spark plasma sinterability and dry sliding wear resistance of tungsten carbide (WC) densified with cobalt (Co), cobalt-nickel (Co+Ni), and cobalt-nickel-chromium (Co+Ni+Cr) binders. Dilatometric spark plasma sintering tests showed that partial substitutions of Co with Ni or Ni+Cr decreased sinterability, with Ni+Cr having a greater negative effect. However, isothermal sintering under pressure was affected little by the substitutions. Testing found the materials were very resistant to dry sliding wear, with WC-Co+Ni+Cr exhibiting the greatest hardness and wear resistance due to its higher
The document discusses cutting tool technology, including tool materials, geometry, and failure modes. It describes how tool life is influenced by cutting speed and material properties. Common tool materials include high-speed steel, cemented carbides, ceramics, and coatings. Tool geometry depends on the operation, with single-point and multiple-point tools discussed. Twist drills are a type of multiple-point tool used for hole making.
Chronological developments in Cutting Tool MaterialsBilal Syed
This is ap resentation showing the developments of cutting tools materials used from early life to present. their materials, properties, advantages, etc.
This document discusses forming limit diagrams (FLDs) for different types of steel sheets, including interstitial free (IF) steels, HSLA steels, and aluminum alloys. It analyzes the FLDs for different thicknesses of IF steel sheets and examines the effects of thickness, coating, microstructure, and other properties on formability. The document also compares the formability of HSLA, microalloyed, and carbon-manganese steels based on their FLDs and considers the effects of properties like strain hardening exponent and anisotropy. Factors influencing void growth and fracture behavior under various stress conditions are also evaluated.
Investigate Temperature Preheating on the Chill Plate to Identify Surface Cha...Natalino Fonseca
1. The document describes an investigation into the effect of temperature preheating on the chill plate to characterize the surface of ductile iron castings.
2. Samples of ductile iron were cast against chill plates that were preheated to different temperatures (500°C, 700°C, 900°C, and unheated) to study the microhardness, surface layer thickness, and elemental composition on the casting surface.
3. Preliminary results found that higher preheat temperatures produced a carbide structure on the casting surface, while no preheating resulted in a fully ferritic microstructure with uniform carbide formation and a pearlite-ferrite microstructure.
. One of the methods used to surface hardening of ductile iron is chilled cast iron. Chill as the fast cooling rate in the mold during solidification and chill thickness greatly affects the thickness of the hardness layer. The main material used is ductile iron, and the chill material is SS 304. Casting uses the sand casting method. Before pouring, the chill plate has been inserted onto the surface of the pattern that has been formed in the mold, then the chill plate is preheated at 700OC. Pouring was carried out at a melting temperature of 1400OC, and then cooled with argon and O2 sprays into the mold in solidification conditions at exactly 700OC. The results analyzed were the microstructure, hardness value, and the hardness of the thickness layer. This chill coolant will absorb heat very quickly and the Cr and Ni alloy will diffuse to the specimen surface to stabilize the ferrite and austenite phases in the final solidification. The particles on the hard surface have Ferro carbide M7C3, which is in the form of cementite and martensitic phases so that to categorized as white cast iron structure formed on the surface with an area around 1.5-3mm has a hardness of 61-65HRC. But in the center area is 31-49HRC
The document discusses various cutting tool materials used in metal cutting operations, including their compositions, properties, and applications. It covers traditional materials like high-speed steel and more advanced materials like cemented carbides, ceramics, and coatings. High-speed steel retains hardness at high temperatures allowing higher cutting speeds than carbon steel tools. Cemented carbides are very hard and can machine at even higher speeds than high-speed steel but are more brittle. Ceramics can operate at the highest speeds of all materials due to their ability to withstand very high temperatures without losing strength or hardness.
Sheet metal forming processes Erdi Karaçal Mechanical Engineer University of ...Erdi Karaçal
The document describes various sheet metal forming processes and provides characteristics of each. It discusses roll forming for parts with complex cross-sections and high production rates but high tooling costs. Stretch forming is described as suitable for low quantity production but with high labor costs and tooling/equipment costs depending on part size. Drawing is outlined as having high production rates but also high tooling and equipment costs.
The document analyzes the formability, fracture behavior, void coalescence, and texture of batch annealed (BA), continuous annealed (CA), and cold rolled (CR) 430 grade stainless steel sheets through tensile testing, forming limit diagrams, fractography, and texture analysis. Microstructural observations found elongated grains in the rolling direction, with average grain size decreasing in the order of CA, BA, and CR sheets. CA and BA sheets exhibited better formability than CR sheets based on forming limit diagrams and texture analysis, though CR sheets still showed satisfactory performance for certain applications.
Dr. R. Narayanasamy - Presentation on Formability of Deep Drawing Grade SteelsDr.Ramaswamy Narayanasamy
Step 1: The document summarizes a presentation given by Dr. Ramaswamy Narayanasamy on the formability of deep drawing grade steels.
Step 2: It provides details of the speaker's achievements and scientific contributions related to sheet metal forming and formability studies on various steel grades.
Step 3: The presentation describes the methodology used to construct forming limit diagrams (FLDs), including the different strain conditions tested, grid circle marking on sheet specimens, measurement of strain after deformation, and plotting of the FLD curves.
This document presents the results of an experimental study on the effect of cutting speed on tool wear of uncoated and coated cemented carbide tools during dry turning of AISI 316 austenitic stainless steel. Turning tests were conducted at three cutting speeds (100, 150, and 200 m/min) with depth of cut and feed rate kept constant. Tool wear was measured and tool life was compared between uncoated and TiN-TiCN-Al2O3-ZrCN multilayer coated inserts. The results showed that cutting speed significantly affected tool wear and tool life decreased with increasing speed. The multilayer coated insert demonstrated superior wear resistance and 25-40% longer tool life compared to the uncoated insert
Dr.R. Narayasamy jindal steels new presentationDrRNaryanasamy
Bendability of Stainless steel 431Grade supplied by Jindal Stainless Steel prepared by Dr. R. Narayansamy, (Retd. Professor, National Institute of Technology,Tiruchirappalli - 620 015)
Chief Metallurgist, Balaji Super Alloys,karamadai-641104, Coimbatore, Tamil Nadu, India.
This document describes an explicit-implicit simulation of square cup deep drawing using forming limit diagrams. The simulation involves:
- Explicit dynamic analysis of deep drawing using an anisotropic sheet material model
- Failure prediction using forming limit diagrams
- Implicit static analysis of springback after removing the punch using explicit results as input
The analysis demonstrates the ability to switch between explicit and implicit solvers in MD Nastran to efficiently simulate the deep drawing process and subsequent springback. Forming limit diagrams are used to predict element failure during drawing.
This document discusses machining processes and metal cutting. It begins with an overview of common machining processes like turning and milling. It then covers topics such as orthogonal cutting, chip formation, different chip types, cutting forces, temperatures in cutting, tool geometry and wear. Diagrams illustrate cutting tool geometry, forces acting on tools, chip formation mechanisms, and experimental data on cutting parameters for different materials. The document provides information on machining processes and metal cutting for engineering materials.
The document discusses a research project analyzing the formability and wrinkling limits of various high strength steel sheets supplied by TATA Steel. Dr. R. Narayanasamy is the principal investigator, studying properties like tensile strength, forming limit diagrams, strain distribution, fractography, and texture. Tests were conducted on interstitial free steel, dual phase steel, and other varieties in thicknesses from 0.6mm to 2.0mm. Charts of chemical composition, microstructure, tensile properties, and forming limit diagrams are presented for each steel type.
IRJET- Experimental Investigation on Partial Replacement of M-Sand by Steel SlagIRJET Journal
This study experimentally investigated the partial replacement of m-sand (natural sand) with steel slag as fine aggregate in concrete. Various concrete mixes were prepared by replacing m-sand with 10%, 20%, 30%, and 40% steel slag by volume. The compressive strength, tensile strength, and flexural strength of the concrete cubes, cylinders, and beams were tested and compared to a conventional concrete mix without steel slag. The results showed that replacing up to 30% of m-sand with steel slag did not negatively impact the strength of the concrete and can be a viable way to utilize an industrial waste product in construction.
This document summarizes a study on the effect of chromium content on the microstructure and wear resistance of Fe-Cr-C hard facing layers. Hard facing layers containing various amounts of chromium were deposited on mild steel using shielded metal arc welding. Testing found that microstructure consisted of primary (Cr, Fe)7C3 carbides and eutectic phases. Higher chromium content refined the carbides. Wear resistance testing found that higher chromium, carbon, and silicon content resulted in higher hardness and less wear. Electrode I, with higher amounts of these elements, exhibited less wear than Electrode II. In conclusion, chromium content significantly affects microstructure and wear resistance, with higher chromium improving hardness and wear performance of Fe
Experimental Investigations on Tribiological Properties of 6061-T6 Al Alloy b...IJAEMSJORNAL
Microstructure and tribological properties of Al-TiB2 nano surface composite fabricated by Friction Stir Processing (FSP) were evaluated. To vary the percentage of TiB2 three different slot thickness viz. 1mm, 1.5 mm and 2mm were considered. Microstructural evaluations showed a nearly uniform distribution of TiB2 in the aluminium matrix after FSP with the addition of composite powder. Microhardness test results shoes FSW of Al6061-T6 alloy with 2mm groove width has more hardness. tribological properties were evaluated at two different sliding velocities 0.314m/s and 0.48m/s and results shows that at lower loads there is no much difference in wear rate of surface composite made with different slot sizes but with increase in load and sliding velocity wear rate was increased , however, larger slot Al6061-TiB2 Surface composites show better wear resistance.
This document reviews additive manufacturing research on cermets. Several powder-based AM processes have been used to produce cermets, including selective laser sintering/melting, laser engineering net shaping, direct laser deposition, and binder jet 3D printing. Research has focused on optimizing process parameters to produce dense, crack-free cermet components and evaluating properties like density and hardness. Key findings include that SLS/SLM of WC-Co is most widely studied and parameters like laser power, scan speed, layer thickness influence microstructure and properties of final parts.
This document summarizes a study on the formability of various Indian stainless steel sheets formed under different stress conditions. Experimental work was conducted to determine the forming limit diagrams, microstructures, tensile properties, crystallographic textures and void characteristics of SS301, SS304, SS409M, SS430 and SSLN1 steel grades. Micrographs showed SS304 has a mixed grain structure while SS301 has coarse grains with carbides. Forming limit diagrams were plotted from strain measurements. Texture analysis was performed using X-ray diffraction. Void size, shape and spacing were analyzed from SEM images. Properties including yield strength, elongation and strain hardening exponent were calculated and correlated with formability.
The document summarizes research characterizing the forming behavior of aluminum alloy AA5754 at elevated temperatures. Key findings from tensile and forming tests are:
1) Yield strength, strain hardening exponent, and flow stress decrease with increasing temperature, while elongation increases.
2) Warm forming from 100-250°C improves formability over room temperature forming.
3) A test setup was developed to evaluate forming limits at elevated temperatures up to 250°C.
Mechanism of Fracture in Friction Stir Processed Aluminium AlloyDr. Amarjeet Singh
Aluminium alloys are used for important
applications in reducing the weight of the component and
structure particularly associated with transport, marine,
and aerospace fields. Grain refinement by scandium (Sc)
addition can eliminate the casting defects and increase the
resistance to hot tearing for high strength aluminium alloys.
FSP for cast aluminium alloys have been focused and it has
great advantages including solid state microstructural
evolution, altering mechanical properties by optimizing
process parameters. These parameters are tool rotational
speeds (720, and 1000 rpm), traverse speeds (80, and 70
mm/min), and axial compressive force at 15 kN, etc. The
mechanical properties had been evaluated on FSPed
aluminium alloy with different microstructural conditions.
Fracture properties of aluminium alloys are very important
for industrial applications. Tensile and fracture toughness
properties were correlated to microstructural and
fractographic features of the aluminium alloys need to
explore their essential failure mechanisms.
The document summarizes a study that investigated the spark plasma sinterability and dry sliding wear resistance of tungsten carbide (WC) densified with cobalt (Co), cobalt-nickel (Co+Ni), and cobalt-nickel-chromium (Co+Ni+Cr) binders. Dilatometric spark plasma sintering tests showed that partial substitutions of Co with Ni or Ni+Cr decreased sinterability, with Ni+Cr having a greater negative effect. However, isothermal sintering under pressure was affected little by the substitutions. Testing found the materials were very resistant to dry sliding wear, with WC-Co+Ni+Cr exhibiting the greatest hardness and wear resistance due to its higher
The document discusses cutting tool technology, including tool materials, geometry, and failure modes. It describes how tool life is influenced by cutting speed and material properties. Common tool materials include high-speed steel, cemented carbides, ceramics, and coatings. Tool geometry depends on the operation, with single-point and multiple-point tools discussed. Twist drills are a type of multiple-point tool used for hole making.
Chronological developments in Cutting Tool MaterialsBilal Syed
This is ap resentation showing the developments of cutting tools materials used from early life to present. their materials, properties, advantages, etc.
This document discusses forming limit diagrams (FLDs) for different types of steel sheets, including interstitial free (IF) steels, HSLA steels, and aluminum alloys. It analyzes the FLDs for different thicknesses of IF steel sheets and examines the effects of thickness, coating, microstructure, and other properties on formability. The document also compares the formability of HSLA, microalloyed, and carbon-manganese steels based on their FLDs and considers the effects of properties like strain hardening exponent and anisotropy. Factors influencing void growth and fracture behavior under various stress conditions are also evaluated.
Investigate Temperature Preheating on the Chill Plate to Identify Surface Cha...Natalino Fonseca
1. The document describes an investigation into the effect of temperature preheating on the chill plate to characterize the surface of ductile iron castings.
2. Samples of ductile iron were cast against chill plates that were preheated to different temperatures (500°C, 700°C, 900°C, and unheated) to study the microhardness, surface layer thickness, and elemental composition on the casting surface.
3. Preliminary results found that higher preheat temperatures produced a carbide structure on the casting surface, while no preheating resulted in a fully ferritic microstructure with uniform carbide formation and a pearlite-ferrite microstructure.
. One of the methods used to surface hardening of ductile iron is chilled cast iron. Chill as the fast cooling rate in the mold during solidification and chill thickness greatly affects the thickness of the hardness layer. The main material used is ductile iron, and the chill material is SS 304. Casting uses the sand casting method. Before pouring, the chill plate has been inserted onto the surface of the pattern that has been formed in the mold, then the chill plate is preheated at 700OC. Pouring was carried out at a melting temperature of 1400OC, and then cooled with argon and O2 sprays into the mold in solidification conditions at exactly 700OC. The results analyzed were the microstructure, hardness value, and the hardness of the thickness layer. This chill coolant will absorb heat very quickly and the Cr and Ni alloy will diffuse to the specimen surface to stabilize the ferrite and austenite phases in the final solidification. The particles on the hard surface have Ferro carbide M7C3, which is in the form of cementite and martensitic phases so that to categorized as white cast iron structure formed on the surface with an area around 1.5-3mm has a hardness of 61-65HRC. But in the center area is 31-49HRC
The document discusses various cutting tool materials used in metal cutting operations, including their compositions, properties, and applications. It covers traditional materials like high-speed steel and more advanced materials like cemented carbides, ceramics, and coatings. High-speed steel retains hardness at high temperatures allowing higher cutting speeds than carbon steel tools. Cemented carbides are very hard and can machine at even higher speeds than high-speed steel but are more brittle. Ceramics can operate at the highest speeds of all materials due to their ability to withstand very high temperatures without losing strength or hardness.
Sheet metal forming processes Erdi Karaçal Mechanical Engineer University of ...Erdi Karaçal
The document describes various sheet metal forming processes and provides characteristics of each. It discusses roll forming for parts with complex cross-sections and high production rates but high tooling costs. Stretch forming is described as suitable for low quantity production but with high labor costs and tooling/equipment costs depending on part size. Drawing is outlined as having high production rates but also high tooling and equipment costs.
The document analyzes the formability, fracture behavior, void coalescence, and texture of batch annealed (BA), continuous annealed (CA), and cold rolled (CR) 430 grade stainless steel sheets through tensile testing, forming limit diagrams, fractography, and texture analysis. Microstructural observations found elongated grains in the rolling direction, with average grain size decreasing in the order of CA, BA, and CR sheets. CA and BA sheets exhibited better formability than CR sheets based on forming limit diagrams and texture analysis, though CR sheets still showed satisfactory performance for certain applications.
Dr. R. Narayanasamy - Presentation on Formability of Deep Drawing Grade SteelsDr.Ramaswamy Narayanasamy
Step 1: The document summarizes a presentation given by Dr. Ramaswamy Narayanasamy on the formability of deep drawing grade steels.
Step 2: It provides details of the speaker's achievements and scientific contributions related to sheet metal forming and formability studies on various steel grades.
Step 3: The presentation describes the methodology used to construct forming limit diagrams (FLDs), including the different strain conditions tested, grid circle marking on sheet specimens, measurement of strain after deformation, and plotting of the FLD curves.
This document presents the results of an experimental study on the effect of cutting speed on tool wear of uncoated and coated cemented carbide tools during dry turning of AISI 316 austenitic stainless steel. Turning tests were conducted at three cutting speeds (100, 150, and 200 m/min) with depth of cut and feed rate kept constant. Tool wear was measured and tool life was compared between uncoated and TiN-TiCN-Al2O3-ZrCN multilayer coated inserts. The results showed that cutting speed significantly affected tool wear and tool life decreased with increasing speed. The multilayer coated insert demonstrated superior wear resistance and 25-40% longer tool life compared to the uncoated insert
Dr.R. Narayasamy jindal steels new presentationDrRNaryanasamy
Bendability of Stainless steel 431Grade supplied by Jindal Stainless Steel prepared by Dr. R. Narayansamy, (Retd. Professor, National Institute of Technology,Tiruchirappalli - 620 015)
Chief Metallurgist, Balaji Super Alloys,karamadai-641104, Coimbatore, Tamil Nadu, India.
This document describes an explicit-implicit simulation of square cup deep drawing using forming limit diagrams. The simulation involves:
- Explicit dynamic analysis of deep drawing using an anisotropic sheet material model
- Failure prediction using forming limit diagrams
- Implicit static analysis of springback after removing the punch using explicit results as input
The analysis demonstrates the ability to switch between explicit and implicit solvers in MD Nastran to efficiently simulate the deep drawing process and subsequent springback. Forming limit diagrams are used to predict element failure during drawing.
This document discusses machining processes and metal cutting. It begins with an overview of common machining processes like turning and milling. It then covers topics such as orthogonal cutting, chip formation, different chip types, cutting forces, temperatures in cutting, tool geometry and wear. Diagrams illustrate cutting tool geometry, forces acting on tools, chip formation mechanisms, and experimental data on cutting parameters for different materials. The document provides information on machining processes and metal cutting for engineering materials.
The document discusses a research project analyzing the formability and wrinkling limits of various high strength steel sheets supplied by TATA Steel. Dr. R. Narayanasamy is the principal investigator, studying properties like tensile strength, forming limit diagrams, strain distribution, fractography, and texture. Tests were conducted on interstitial free steel, dual phase steel, and other varieties in thicknesses from 0.6mm to 2.0mm. Charts of chemical composition, microstructure, tensile properties, and forming limit diagrams are presented for each steel type.
IRJET- Experimental Investigation on Partial Replacement of M-Sand by Steel SlagIRJET Journal
This study experimentally investigated the partial replacement of m-sand (natural sand) with steel slag as fine aggregate in concrete. Various concrete mixes were prepared by replacing m-sand with 10%, 20%, 30%, and 40% steel slag by volume. The compressive strength, tensile strength, and flexural strength of the concrete cubes, cylinders, and beams were tested and compared to a conventional concrete mix without steel slag. The results showed that replacing up to 30% of m-sand with steel slag did not negatively impact the strength of the concrete and can be a viable way to utilize an industrial waste product in construction.
This document summarizes a study on the effect of chromium content on the microstructure and wear resistance of Fe-Cr-C hard facing layers. Hard facing layers containing various amounts of chromium were deposited on mild steel using shielded metal arc welding. Testing found that microstructure consisted of primary (Cr, Fe)7C3 carbides and eutectic phases. Higher chromium content refined the carbides. Wear resistance testing found that higher chromium, carbon, and silicon content resulted in higher hardness and less wear. Electrode I, with higher amounts of these elements, exhibited less wear than Electrode II. In conclusion, chromium content significantly affects microstructure and wear resistance, with higher chromium improving hardness and wear performance of Fe
Experimental Investigations on Tribiological Properties of 6061-T6 Al Alloy b...IJAEMSJORNAL
Microstructure and tribological properties of Al-TiB2 nano surface composite fabricated by Friction Stir Processing (FSP) were evaluated. To vary the percentage of TiB2 three different slot thickness viz. 1mm, 1.5 mm and 2mm were considered. Microstructural evaluations showed a nearly uniform distribution of TiB2 in the aluminium matrix after FSP with the addition of composite powder. Microhardness test results shoes FSW of Al6061-T6 alloy with 2mm groove width has more hardness. tribological properties were evaluated at two different sliding velocities 0.314m/s and 0.48m/s and results shows that at lower loads there is no much difference in wear rate of surface composite made with different slot sizes but with increase in load and sliding velocity wear rate was increased , however, larger slot Al6061-TiB2 Surface composites show better wear resistance.
Experimental investigations of surface wear by dry sliding and induced damage...Barhm Mohamad
This study concerns the wear behaviour of metal couples used in industry, particularly in mechanical sliding systems (numerically controlled machine tools). In general, the nature of the materials of the parts of these systems which are in contact and move relatively, are medium carbon steels, thanks to their good mechanical and tribological properties. The present work aims to study, the dry sliding wear of the contact surface of the pin (machine slide) against the contact surface of a disc (machine groove) and the damage induced on the worn track. The pin is AISI 1038 and AISI 1045 steel, the disc is AISI 1055 steel. The tribological tests were carried out on a pin-disc tribometer, in an atmospheric environment. The wear of the pins being evaluated by weighing and studied according to the hardness of the pin with the variation of the normal load applied. The discussion of the results is based on SEM observations and EDS analyzes of worn surfaces and interfacial phenomena produced by dynamic contact. The results obtained indicated the influence of the applied load and the hardness on the wear of the pin and therefore on the tribological behaviour of the worn surfaces.
Influence of volume fraction, size, cracking, clustering of particulates and ...eSAT Journals
Abstract
The objective of this study is to examine the influence of volume fraction, size of particulates, formation of precipitates at the
matrix/particle interface, particle cracking, voids/porosity, and clustering of particulates on the strength and stiffness of
6063/SiCp metal matrix composites. Tensile strength and stiffness increase with an increase in the volume fraction of SiC
particulates. The tensile strength and stiffness decrease with increase in size of the particulates, presence of porosity, clustering,
and particle cracking. Formation of particulate clusters is more prominent in the composites having very small-reinforced
particulates. Mg2Si compound is likely to precipitate at the matrix/particle interfaces of 6063/SiC composite.
Keywords: 6063, SiC, clustering, cracking, porosity, clustering
This document summarizes a study that investigated the mechanical and metallurgical properties of friction stir welded AA1100 aluminum alloy joints. Different welding parameters were tested, including tool rotation speed (800-1400 rpm) and material positioning (advancing vs. retreating side). Microhardness, tensile, and fracture surface tests were used to evaluate the mechanical properties. Optical and SEM microscopy were used to analyze the microstructural evolution. The goal was to understand how processing parameters affect properties and defect development in similar AA1100 alloy joints.
ANALYSIS OF TOOL WEAR IN TURNING OPERATION OF ALUMINIUMIRJET Journal
The document analyzes tool wear during aluminum turning operations using high-speed steel tools. Experiments were conducted varying cutting speed, feed rate, and depth of cut to collect tool wear and cutting force data. The results were analyzed to determine optimal cutting parameters that minimize tool wear and maximize tool life when machining aluminum. Specifically, the study aimed to identify the cutting speed, feed, and depth of cut combination that causes the least tool wear, as well as determine the maximum and minimum tool wear levels at different cutting speeds. The results provide insights into improving tool performance and efficiency during aluminum machining.
1) An analysis was conducted to determine the effects of cutting speed, feed rate, and use of cutting fluid on tool wear and surface roughness when turning AISI 304 stainless steel.
2) The analysis found that cutting speed had the greatest influence on tool wear, while feed rate had the greatest influence on surface roughness.
3) Both tool wear and surface roughness decreased with increasing cutting speed up to 175 m/min and decreasing feed rate from 0.4 to 0.2 mm/rev. The use of cutting fluid also improved results.
Regression analysis of shot peening process for performance characteristics o...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Investigation and analysis of metallurgical and mechanical properties of aa11...Alexander Decker
1. The document investigates the mechanical and metallurgical properties of friction stir welded joints of AA1100 aluminum alloy fabricated at different tool rotational speeds and material positions.
2. Tensile tests, microhardness tests, and optical/SEM microscopy of the welds were used to evaluate the mechanical properties and microstructure of the joints.
3. The results showed that joints welded at 1200 rpm had the optimum properties, with smooth weld surfaces and good tensile strength, yield strength, and elongation. Microhardness was also highest at this welding condition.
A Review on Mechanical and Wear Behaviour of Aluminium Metal Matrix CompositesIRJET Journal
This document reviews the mechanical and wear behavior of aluminum metal matrix composites (AMMCs). It discusses various fabrication techniques for AMMCs, with stir casting being the most commonly used due to its low cost and simplicity. The document evaluates literature on the mechanical properties and wear resistance of different AMMC materials and compositions fabricated by various methods. In general, adding ceramic reinforcements like silicon carbide and aluminum oxide improves the hardness and wear resistance of aluminum composites compared to the unreinforced alloy.
IRJET- Emphasis of Plate-Thickness and Groove Angle on Distortion for Mild St...IRJET Journal
The document summarizes research into minimizing welding distortion, which is a change in shape that occurs between welded plates before and after welding. The research investigates the effect of plate thickness (6, 7, and 8mm) and groove angle (60, 90, and 120 degrees) on angular distortion in mild steel butt joints welded using manual metal arc welding (MMAW). Mathematical models are developed using response surface methodology to predict transverse and longitudinal shrinkage distortion based on plate thickness and groove angle. Analysis of variance (ANOVA) testing shows that the models accurately predict distortion. The research aims to provide empirical data to better understand different types of welding distortion.
IRJET- Material Characterization on Functionally Graded AL-CU Alloy Fabricate...IRJET Journal
This document summarizes a study that characterized the material properties of an Al-Cu alloy fabricated using centrifugal casting at different rotational speeds. Specifically:
- An Al-Cu alloy was centrifugally cast at 400rpm, 600rpm, and 800rpm to produce functionally graded materials with varying properties along the radial direction.
- Testing found that hardness and tensile strength increased with rotational speed, with the 800rpm alloy exhibiting the finest grain structure and highest properties.
- Microstructures showed finer grains and higher hardness at the inner and outer surfaces due to more rapid solidification, with coarser grains and lower hardness in the middle.
IRJET - Tribological Characteristics of Al-SIC-MOS2 Cylindrical Powder Prefor...IRJET Journal
The document summarizes the tribological characteristics of Al-SiC-MoS2 cylindrical powder preforms under dry atmospheric conditions. It discusses conducting wear tests using a pin-on-disc apparatus against silicon carbide abrasive paper under various testing conditions such as applied load, sliding velocity, and time. The wear is measured by weight loss and the relationship between weight loss and applied load is established. Materials used include aluminum, silicon carbide, and molybdenum disulfide powder preforms compacted at different pressures and sintered at one temperature.
Effect of pin profile on friction stir welded aluminum matrix compositesAsif Ali
The document discusses the effect of pin profile geometry on friction stir welded aluminum matrix composites. It finds that a square pin profile produces welds with smaller and finer grains compared to hexagonal and octagonal pin profiles. This leads to improved hardness, tensile strength, and wear resistance due to the relationship between smaller grain size and better mechanical properties. The square pin profile causes less heat input during welding, resulting in less grain growth and better properties compared to the other pin profiles tested. Increasing welding speed and decreasing rotational speed also reduce heat input and improve properties by limiting grain growth during cooling.
WEAR STUDIES ON THE HEAT TREATED AL6061-μSIC AND AL6061-NSIC METAL MATRIX COM...IAEME Publication
Metal matrix composites (MMCs) have a potential for enhanced wear conflict in
excess of the unreinforced aluminum alloy and are the most capable in achieving
enhanced mechanical properties. In the present investigation, composites of Aluminum
6061(Al6061) matrix material is reinforced with micron size Silicon carbide (μSiC)
reinforcement with 5, 10 and 15 weight percentages (wt.%) and nano size SiC (nSiC)
with 0.5, 1.0 and 1.5 wt.% are fabricated by stir casting technique. The stir casted
composites are further heat treated and the specimens are prepared as per ASTM
standards to conduct hardness and wear tests. The fabricated and heat treated nano
composites showed enhancement in hardness and wear resistance more than the micro
composites. The microstructure of the worn out specimen are examined by scanning
electron microscope. Taking into contemplation all the factors, it can be concluded that
aluminum based composite with 1.0% by weight nano SiC reinforcement acquire
superior wear resistance properties as compared to micro SiC reinforced aluminum
metal matrix composites.
FEM Analysis of Stress Predication of Aluminum Wire Rod in Drawing OperationIRJET Journal
This document analyzes aluminum wire drawing operations to understand causes of wire breakage. Finite element analysis is conducted using ANSYS to simulate wire stresses, strains, die stresses, and temperatures at critical drawing stages. The analysis considers different friction conditions to find optimal parameters that minimize defects and breakage. Material properties of the aluminum alloy wire and polycrystalline dies are defined. Simulation results reveal plastic deformation patterns and maximum stresses under various lubrication conditions to suggest preventative measures and reduce breakage during drawing.
The machining process is essential in the manufacturing industry. Among the all
machining process, turning is the broadest techniques used to remove the metal. In
this machining process, metal removal rate was influenced by the sharpness of the
cutting tools. Due to the friction between the workpiece and the tool insert, tool wear
occurs. After the wear takes place, the efficiency of the machine will be reduced and
metal removal time will be increased. Hence, it is essential to investigate the
behaviour of the tool wear under the machining. This investigation is to analyse the
wear characteristics of the tool inserts. The machining of the EN8 was examined in
this research using silicon carbide tool inserts and Titanium nitride coated tool
inserts. This research was investigated the wear behaviour of the silicon carbide tool
insert, and titanium nitride tool insert in machining of EN8 steel using a horizontal
machining centre. The wear of the inserts was measured using toolmakers
microscope. The flank wear and crater wear was considered in the tool wear
measurement.
Influence of Elastic Deformations on the Adhesion of the ZRN Coating on the C...ijtsrd
Clinching is a mechanical joining method. Is it utilized in automobile industry as an alternative method to resistance spot welding. Considering that various types of materials are joined in car body production, PVD coatings are used to increase the lifetime of the clinching tools. Hot dip galvanized steel sheets were used for joining by clinching method. The zirconium nitride ZrN PVD coating was deposited on the surfaces of clinching tool. The loss of cohesion properties of coating was observed at punch´s R0.2 radius after 300 clinched joints. FEM analysis was used to show the punch´s critical part when the tool is under load. LuboÅ¡ KaÅ¡c¡k | Renâ Kubk "Influence of Elastic Deformations on the Adhesion of the ZRN Coating on the Clinching Tool" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-1 , December 2019, URL: https://www.ijtsrd.com/papers/ijtsrd29856.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/29856/influence-of-elastic-deformations-on-the-adhesion-of-the-zrn-coating-on-the-clinching-tool/lubo%C5%A1-ka%C5%A1c%C3%A1k
Investigation on the Creep Behaviour of Friction Stir Processed Al Ni Composi...ijtsrd
Indentation creep experiments were carried out on friction stirred Aluminum Nickel composite. The samples were cut from Al Ni plate which was undergone by friction stir processing. The specimen was polished by different polishing methods to reveal the macro and micro structure of the material. The macro structure contains two zones base metal zone and friction stirred zone . Creep tests were carried out on both friction stirred and base metal region of test specimen at different temperatures with different loads. It was found that there was a significant difference between the creep rates of friction stirred region and that of base metal region when tested under various conditions. The Activation energy determined was found to in the range of 45KJ Mole to 55KJ Mole at lower temperatures. Based on these results it can be concluded that the operative mechanism is the dislocation creep. But at higher temperature the Activation energy was found to be in the range of 140KJ Mole to 170KJ Mole so the operative mechanism for creep is diffusion creep. Samples were metallographic ally prepared and the microstructures were studied under optical and scanning electron microscope. Results of the experiments were discussed. Marripally Ravikumar "Investigation on the Creep Behaviour of Friction Stir Processed Al-Ni Composite Material" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1 , December 2020, URL: https://www.ijtsrd.com/papers/ijtsrd38145.pdf Paper URL : https://www.ijtsrd.com/engineering/mechanical-engineering/38145/investigation-on-the-creep-behaviour-of-friction-stir-processed-alni-composite-material/marripally-ravikumar
A STUDY OF EFFECT PROCESS PARAMETERS ON TENSILE STRENGTH IAEME Publication
This document discusses a study on the effect of process parameters on tensile strength of friction stir welded AA6061 aluminum alloy joints. Friction stir welding is a solid-state joining process that uses a non-consumable rotating tool to join materials together without melting. The study examines parameters like rotational speed, traverse speed, axial force, shoulder diameter, and tilt angle. Tensile test samples were prepared and tensile strength values were measured for different parameter combinations based on a Taguchi design of experiments. Optimum tensile strength was found at 1000 rpm speed, 14 mm/min feed rate, 7 kN axial force, 17 mm shoulder diameter, and 3° tilt angle for cylindrical tools and 710 rpm speed,
Similar to Tool wear and inclusion behaviour during turning of a calcium treated quenched and tempered steel using coated cemented carbide tools (20)
Analytical prediction of flank wear of carbide tools in turning plain carbon ...Lepuufu
The document analyzes flank wear characteristics of tungsten carbide tools when turning plain carbon steels. It finds that flank wear can be described by an equation similar to the one used for crater wear, but with two characteristic lines intersecting at around 1150K. Experiments measuring temperature and stress on the flank wear land support this, finding uniform distributions. The constants in the flank wear equation are affected by abrasives in the steels. Further investigation is needed to fully understand the contribution of abrasion to flank wear.
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The behaviour of materials in machining the influence of small tellurium ad...Lepuufu
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Specific reduction of toxic side effectsof adriamycin by induction of metallo...Lepuufu
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against developing mental illness and improve symptoms for those who already have a condition.
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Historical analysis of metal cutting shows that metal removal rates have been increasing in the course of the century, predicated by the advancement in tool materials but the steel design has lagged behind. This paper examines the mechanisms of chip formation and tool wear as a function of cutting speed in metal cutting. Chemical wear is identified as the dominant mechanism of tool wear at high cutting speeds caused by temperature rise due to shear localisation in the primary and secondary shear zones of chip. Shear localisation in the primary shear zone is shown to be influenced by both microstructural parameters, i.e. matrix hardening and second phase particles, and metal cutting variables, i.e. cutting speed (strain rate) and feed (pressure).
Influence of tellurium addition on drilling of microalloyed steel (din 38mns6)Lepuufu
This study evaluated the influence of tellurium content and minimum quantity lubrication (MQL) flow rate on drilling performance when drilling microalloyed steel. Two grades of steel were tested, one with high tellurium content and one with low tellurium content. Drilling tests were conducted using two cutting speeds, two feed rates, two drill geometries, and two MQL flow rates. Statistical analysis showed that tellurium content most significantly impacted performance, doubling drill life for the high tellurium steel. MQL flow rate had the lowest influence, with a higher flow only reducing life 9%. Addition of tellurium improved machinability by reducing forces during chip formation.
Desenvolvimento de aço com usinabilidade melhoria para moldes para plástico d...Lepuufu
A fabricação de moldes de grande porte exige a produção na aciaria de lingotes de
dimensões acima do usual. De forma a garantir a polibilidade do produto acabado, o material
não pode apresentar forte segregação, nível elevado de inclusões não metálicas ou
porosidades. Para tanto, é necessária a obtenção de reduzidos teores de enxofre e a execução
de elevada deformação mecânica no processo de conformação, principalmente em se
tratando de grandes lingotes. Contudo, a redução do teor de enxofre prejudica a
usinabilidade o que, sem outras alterações, encarece a fabricação do molde. Neste trabalho, é
apresentada a tecnologia de fabricação do bloco para o maior molde já produzido com aço
manufaturado no Brasil no qual o teor de enxofre foi reduzido abaixo de 50 ppm e a
usinabilidade foi mantida através da modificação da morfologia das inclusões através da
desoxidação por cálcio.
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Surface residual stresses due to turning operations in AISI 304 type stainless steel were studied as a function of machining speed, feed rate,
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conditions and tool on the residual stresses were discussed in terms of mechanically and thermally induced non-homogeneous plastic
deformation of the surface layers of the workpiece.
Determining the influence of cutting fluids on tool wear and surface roughnes...Lepuufu
Knowledge of the performance of cutting fluids in machining different work materials is
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efficiency can be evaluated based on certain process parameters such as flank wear, surface
roughness on the work piece, cutting forces developed, temperature developed at the tool
chip interface, etc. The objective of this work is to determine the influence of cutting fluids
on tool wear and surface roughness during turning of AISI 304 with carbide tool. Further
an attempt has been made to identify the influence of coconut oil in reducing the tool
wear and surface roughness during turning process. The performance of coconut oil is also
being compared with another two cutting fluids namely an emulsion and a neat cutting oil
(immiscible with water). The results indicated that in general, coconut oil performed better
than the other two cutting fluids in reducing the tool wear and improving the surface finish.
Coconut oil has been used as one of the cutting fluids in this work because of its thermal
and oxidative stability which is being comparable to other vegetable-based cutting fluids
used in the metal cutting industry.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
ANAMOLOUS SECONDARY GROWTH IN DICOT ROOTS.pptxRASHMI M G
Abnormal or anomalous secondary growth in plants. It defines secondary growth as an increase in plant girth due to vascular cambium or cork cambium. Anomalous secondary growth does not follow the normal pattern of a single vascular cambium producing xylem internally and phloem externally.
BREEDING METHODS FOR DISEASE RESISTANCE.pptxRASHMI M G
Plant breeding for disease resistance is a strategy to reduce crop losses caused by disease. Plants have an innate immune system that allows them to recognize pathogens and provide resistance. However, breeding for long-lasting resistance often involves combining multiple resistance genes
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Tool wear and inclusion behaviour during turning of a calcium treated quenched and tempered steel using coated cemented carbide tools
1. 209
TOOL WEAR AND INCLUSION BEHAWOUR DURING
TURNING OF A CALCIUM-TREATED QUENCHED AND
TEMPERED STEEL USING COATED CEMEmD
CARBIDE TOOLS*
Tool wear, layer formation and deformation behaviour of difkrent inclusion
types in the flow zone of the chip and in the chip-tool interface have been
studied during turning of a calcium-treated quenched and tempered steel
SS2541 (En24, SAE4337) using Tic-Al&-_-coated cemented carbide
inserts. The analysis of inclusions in the flow zone was based on semiautomatic
image anaIysis in a scanning electron microscope. A large adherence in
deformation behaviour between different incfusion types was observed. The
iniluence of Merent inclusions on tool wear and on the forma&m of protective
layers on the tool surface is discussed along with the active wear mechanisms
on tool surface. Dissolution of the coatings into adhered inclusion phases
is indicated as an important wear mechanism, especially when machining
calcium-treated steel with high amounts of calcium-rich sulphides.
1.Intmductiun
It is well established that inclusions in steel have a strong influence on
tool wear in Mach. The effects of sulphur addition and calcium treatment
have been studied extensively during the last two decades fl-S]. These
investigations have led to a qualitative understanding of how different types
of inclusions participate in the wear process. The information has been gained
through studies of the static properties of inclusions or of the corresponding
substances, of their morphologies in the as-rolled steels and through the
wear patterns on the tools. It can be expected that the effect of the inclusions
during wear is controlled by their behaviour in the heavily sheared zones
of the chip or the workpiece facing the tool and on the chip-tool contact
surfaces. This has, however, not been studied previously to our knowledge.
Instead, the deformation behaviour of the inchrsions just before tool contact
*Paper presented at The fnsttute af Met& 1st InternationalConference on the Behaviour
of Materials in Machining, Stratford-upon-Avon,U.K., November S-IO, 1988.
Elsevier Sequoia/Printedin The Netherlands
2. 210
has been estimated from their defo~ab~~ during hot rolling. This has been
evaluated through the shape factors of inclusions in the work material. This
means that the large differences in forming conditions during hot working
and chip formation were not considered. The action of the inclusions during
the tool contact was studied through the wear pattern on the tools and
through the possible presence of protective layers caused by the inclusions
on the tool surfaces. No direct observations of inclusion behaviour in tool
contact were thus made. This means that information is missing on the actual
behaviour of inclusions inside the chip and on the contact surfaces between
the chip, the workpiece and the tool.
The purpose of the present paper is f%stly to describe in a qu~ti~tive
way how different inclusion types in a calcinm-treated quenched and tempered
steel deform in the heavily sheared zone of the chip close to the tool surface,
the secondary deformation zone or the flow zone. This is accomplished by
shape factor determination for inclusions in sections of chips. An image
analyser based on the scanning electron microscope @EM) is utilized, Chips
from turning tests using coated cemented carbide cutting inserts have been
studied. The behaviour of different inclusions in actual contact with the tool
surfaces, both rake and flank, is examined primarily on the side of the chip
contacting the tool and on the machined workpiece. The influence on tool
wear and layer formation is discussed for different inclusion types.
Secondly, the tool surfaces are studied for traces of inclusions and wear
marks. The wear of the coatings at different positions of the cutting insert
is examined and the active tool wear mechanisms during machining are
identified. This paper is devoted to wear mechanisms rather than to tool life
data.
2. Work material
The present study is performed on a calcium-treated quenched and
tempered steel of the type SS2541 (En24, Sm4337). The composition of
the steel is given in Table I. The steel was chill cast and hot rolled to a
diameter of 85 mm and studied in quenched and tempered con&tion. The
mechanical properties are given in Table 2.
3. Inclusions
The amount of different types of inclusions in the work material is shown
in Fig. 1. Mixed sulphides (Mn,Ca)S make up the largest part of the incl~ion
TABLE 1
Chemical composition of the cat&m-treated quenched and tempered steel SS2541 used in
the machining tests
Element c si Mn P S Cr Ni MO Al
AWWWG?(wt.%) 0.38 0.30 0.76 0.005 0.024 1.45 1.30 0.20 0.013
3. 211
TABLE 2
Mechanical properties of the work material in quenched and tempered condition
Yield strength 870 MPa
Ultimate tensile strength 1000 MPa
Fracture elongation (5d) 19%
Area reduction 61%
Hardness HB5/750 300
0.10 -
Pfllr//lAOthers
Duplex
Ca-
aluminate
7
r
I5
Mixed
%OPS-
sulphide
z (Mn.b)S
0
2
=
z
MnS
Fig. 1. The amount of different inclusion types in the work material.
volume in the steel. The other main types are manganese sulphides and
duplex calcium aluminates. The deformation behaviour during chip formation
has been analysed for these three inclusion types. Mn3 is very common in
both untreated and calcium-treated steels. MnS and CaS are completely soluble
in each other at high temperature. In the same steel, mixed sulphides with
very low calcium content can be found as well as almost pure CaS. Although
the relative number of mixed sulphides with very high calcium content is
often low, they are assumed to be very important for the wear of the coatings
on the tool surface. Hardness and deformability of the mixed sulphides
depend on the calcium content. Duplex inclusions are typical for calcium-
treated steels. In most cases they are made up of an oxidic inclusion surrounded
by (MnCa)S. The composition of the oxidic core may vary, depending on
pre-deoxidation.
The plastic deformation of an inclusion can be quantified using the
length-to-thickness ratio (shape factor). The value of this shape factor depends
on inclusion type, applied load, temperature and also particle size. For
inclusions with high deformability, such as Mn3, the shape factor value
increases with increasing particle size. In Table 3 examples are given of
shape factor values for inclusions in longitudinal sections of rolled bar prior
to machining. When the inclusions pass through the different deformation
zones during chip formation, they may be further deformed.
4. 212
TABLE 3
Examples of experimentally determined shape factor values (length f thickness) for different
types of inclusions in rolled bar prior to machining
Inclusia type Shape factor
Mns 6
(Mn,Ca)S 3.5
Duplex calcium aluminate 3.4
TABLE 4
Machining test conditions and tool material data
mg
Speed v=208 m min-’
Feed s=O.3 mm rev-’
Depth of cut a=2 mm
Tic -A1203 -TiN-coated cemented carbide
(GC415 from Sandvik Coromant)
Geometry IS0 TNMM 160408
4. Machining tests
Chips from turning tests were used in the inclusion studies. Cutting
conditions and tool material data are listed in Table 4. The cutting inserts
were coated with three different types of coatings: next to the cemented
carbide matrix a Tic coating 5 pm thick, followed by an AlsO coating 3
pm thick and finally by a very thin (0.1 pm) TiN coating. The identification
of the different types of coatings on the worn cutting inserts was based on
energy-dispersive X-ray (EDX) analysis in the SEM.
5. Image analysis of inclusions in the flow zone
For the analysis of inclusion deformation behaviour in the flow zone,
an SEM-based automatic image analyser has been used. The system combines
automatic image analysis (geometrical classification) with a qualitative EDX
analysis of individual inclusions. The system description, working principles
and examples of practical applications in inclusion analysis are given in
ref. 9.
Software and a methodology for the analysis of inclusions in the flow
zone have been developed. The analysis is based on the study of chips from
the machining tests. Therefore no special types of experiments (e.g. quick
stops) have to be performed and large amounts of test samples are easily
available. The chips were normally coated with nickel to prevent edge rounding
during grinding and polishing. Specimen preparation included mounting,
5. 213
Free
/
surface of chip
structur;l
line
SHAPE FACTOR = XLlYL SHEAR :AXIAY=cot Q
Fig. 2. Schematic view of inclusion appearance in the image analyser during the analysis of
inclusion deformation behaviour in the flow zone.
grinding and diamond polishing according to conventional methods. Lon-
gitudinal, tmetched sections of the chips were studied.
The appearance of the inclusions in the image analyser is shown sche-
matically in Fig. 2. The chip surface facing the tool is included in the image
frame in order to calculate the shear strain and the distance from the tool
rake face to the inclusion. The high resolution of the SEM makes it possible
to detect very small and heavily deformed particles. The evaluation of
geometrical parameters (inclusion size, shape, position and shear) and the
X-ray analysis of each inclusion are performed fully automatically.
6. Deformation of different inclusion types in the flow zone
In this section the deformation behaviour in the flow zone will be
discussed for the different inclusion types in the work material. For each
inclusion type the shape factor values are given as a function of the shear
in the flow zone (or distance from the tool) and of the inclusion size. Shape
6. 214
factor values in the workpiece before machiniug are indicated on the left-
hand side of the diagrams (W).
Of vital importance for tool wear and layer formation is the behaviour
of the inclusions when they are coming in contact with the tool surfaces.
Inclusions which have been sliding against the rake and flank faces of the
inserts have been studied on the chip surface and on the workpiece surface
respectively. For the chips investigated the thickness of the flow zone was
approximately 30% of the chip thickness.
MnS inclusions close to the tool surface are heavily deformed because
of the high shear strain in the flow zone. Especially for relatively large
inclusions, extremely high shape factors (greater than 20) were recorded
close to the rake face (Fig. 3(a)). When the particle size decreases, so does
1
OISTANCTFROMRAJCE WRFACE
Fig. 3. (a) Shape factor values for MnS as a function of the shear in the flow zone. (b) Heavily
deformed manganese sulphides in the now zone.
7. 215
the shape factor value. Close to the tool the shape factors for small MnS
are relatively low. This is due to fragmentation of long, heavily deformed
sulphides into smaller particles with low shape factor. The plastic deformation
of the sulphides is much higher in the flow zone compared to the primary
shear zone. This can be concluded by comparing the recorded values with
the shape factors for inclusions in the workpiece prior to machining (W).
MnS inclusions in the flow zone are shown in Fig. 3(b). Close to the
tool surface the sulphides are so elongated that they are hard to resolve,
even when using SEM. The high deformability of the sulphides makes them
very hard to observe on the chip surface. Occasionally, traces of thin sulphide
hlms can be detected.
MnS probably causes no mechanical, abrasive wear of the tool surface.
The hardness of the inclusions is too low. At low cutting speed (V< 150 m
nun-‘) MnS layers can be detected on carbide tools. These layers may protect
the tool and decrease the diffusion type of wear. However, at high cutting
speed the strength of the sulphide is too low to withstand the contact load
during machining. Adhered sulphide phase will therefore be tom away and
no layer build-up will occur.
6.2. Mixed s&phi&, (Mn,Ca)S
The shape factor values for (Mn,Ca)S are generally lower than for MnS
when data for the same inclusion size are compared. Large (Mn,Ca)S inclusions
can reach high values (X,/u,= 15), but in most cases the values lie in the
internal X,/Y-- = 4-6 (Fig. 4(a)). Probably (Mn,Ca)S inclusions with different
calcium content are included in the analysis, which explains the unexpected
variations in shape factor value for small inclusions.
Fig. 4. (a) Shape factor values for (Mn,Ca)S as a function of the shear in the flow zone. (b)
Comparison of the deformability in the flow zone between an (Mn,Ca)S and sn Mns. (c) An
(Mn,Ca)S and a calcium-containing oxide on the chip surface.
8. 216
The difference in deformability between MnS and (Mn,Ca)S is illustrated
in Fig. 4(b). The size of the particles and the distance from the tool surface
are approximately the same for both inclusions. The MnS is much more
elongated. Due to their low deformability in the flow zone, (Mn,Ca)S can be
observed on the chip surface. Figure 4(c) shows an (Mn,Ca)S lying close
to a calcium ahnninate. Both particles appear to be consumed in a slicing-
off process, leaving the inclusion surface at the same level as the chip surface.
No cavities can be seen in the interface between inclusion and steel matrix.
It is assumed that in order to form layers on the tool surface, it is
necessary for the inclusions to be sliced off and smeared out in the chip-tool
interface. The mixed sulphides often play an spout role in the fo~ation
of layers on carbide tools, both as free inclusions and as part of duplex
inclusions. Their higher hardness compared to the MnS gives the (Mn,Ca)S
a suitable deformation behaviour in the flow zone and in the chip-tool
interface. Similar to MnS, the abrasive wear due to (Mn,Ca)S is thought to
be negligible. However, in some cases tool wear due to dissolution may be
increased because of an tmfavourable combination of tool material and
composition of the (Mn,Ca)S inclusions.
6.3. Duplex calcium aluminate
Duplex calcium-containing inclusions are common in calcium-treated
steels. In most cases the oxidic part of the inclusions is either a calcium
aluminate or a CaAl silicate. In this section the behaviour of duplex calcium
aluminates wiII be discussed. In the investigated materials their normal
appearance is a practically spherical, calcium and ahnninium-containing,
oxidic core surrounded by a mixed sulphide, (Mn,Ca)S.
When the shear in the flow zone is low, high shape factors can be
registered (Fig. 5(a)). Increasing shear close to the tool face results in
decreasing shape factor. No influence of inclusion size can be detected. This
somewhat confusing result is contrary to those for MnS and ~,~a)S, but
can be explained by studying Fig. 5(b). A high shape factor at low shear
levels corresponds to plastic deformation of the sulphide phase (Fig. 5@1)).
When the shear is increasing, the sulphide is separated from the calcium
aluminate, leaving the oxide with only remnants of strIphide phase. This
process results in a decrease in shape factor for the duplex particle. In Fig.
5@2) a calcium aluminate with only a thin sulphide tail is shown close to
the tool. Even though the shear and the temperature are very high in this
part of the flow zone, the spherical shape of the oxide is untiected.
In Fig. 5(c) the remaining sulphide phase can be seen on the chip
surface as a dark rim around the calcium aluminate. The duplex inclusion
appears to be sliced off without any cavity formation in the inclusion-matrix
interface, similar to the (Mn,Ca)S inclusions.
Both the calcium ahuninate and the surrounding (Mn,Ca)S phase are
thought to contribute to the layer formation on carbide tools. This conclusion
is supported by the favourable deformation behaviour in the chip -tool
interface. The absence of plastic deformation of the calcium aIuminates in
9. 217
Fig. 5. (a) Shape factor values for duplex calcium aluminates as a function of the shear in
the flow zone. (b) Duplex calcium aluminates in the flow zone: (hl) 30 q, (b2) 5 w from
the tool surface. (c) A duplex calcium aluminate on the chip surface.
the flow zone indicates that the hardness of the oxides is substantially higher
than for the mixed sulphides. The calcium-containing oxides are thought to
contribute to the abrasive wear of the tool. However, the abrasive wear is
much less than for A1203 inclusions in untreated steels. An important effect
of the calcium treatment is to eliminate the harmful, abrasive ahunina inclusions
and to replace them with more favourabIe ~~ci~-~ou~g oxides.
6.4. InclM behaviow on the tool Jkmk
The deformation behaviour of inclusions sliding against the flank face
of the tool can be studied on the workpiece surface. For calcium-containing
inclusions the deformation behaviour is simiiar to the behaviour on the chip
surface. lhe oxides are sliced off and ~~ci~~on~ sulphides are heavily
deformed and smeared out in the same way as in the flow zone.
7. Tool wear
7-f. Wear pattern
A worn cutting insert is shown in Fig. 6 after 10 mm of machining.
Several different zones with different wear of the coatings can be distinguished
along the cutting edge. The differences in wear rate and composition of the
tool surface between different parts of the tool are considerable. On the
very cutting edge (zone A) the A&O:, coating and the thin TiN coating are
still present. In zones B and E on the rake and flank surfaces respectively
the TiN and A120, coatings are completeIy consumed and only part of the
Tic coating is still left. In the nose area in zone B the Tic coating is worn
through and work material fills a crater in the cemented carbide. Adhered
10. Fig. 6. View of a worn tool after 10 min of turning with thin CaS inclusion layers on the tool
surface, especially in zones A, B and C; cutting speed 208 m min-‘. A, A1203+TiN; B, Tic;
C, Alz03; D, (Mn,Ca)S inclusion layer; E, TIC; F, A1203.
inclusion layers were observed on the tool surface. Considerable differences
in layer composition and layer thiclmess between different areas were detected.
In zones A and B the tool surface is covered with a thin CaS layer. In zone
D, 0.35475 mm from the cutting edge, the tool surface is covered with
a relatively thick (Mn,Ca)S inclusion layer. The composition of the inclusion
layers was analysed using an Auger technique. Using depth profiling it was
shown that no significant amounts of elements other than manganese, calcium
and sulphur were present in the layers. The oxygen content was negligible.
The different zones with different wear and surface composition are
clearly visible in the backscattered image in Fig. 7(a). In Fig. 7(b) the
remaining A1203 coating on the cutting edge is visible and also the narrow
section through the Al,Oa coating (zone C) marking the transition from the
worn ‘DC coating in zone B to the (Mn,Ca)S layer in zone D. Figure 8 shows
a part of the (Mn,Ca)S layer on the rake face (zone D). The thickness of
the layer is approximately 10 pm.
The cracks in the layer are probably due to thermal stresses during the
machining tests. Because of the cracks, small pieces of the layer have been
lost. The exposed tool surface under the inclusion layer displays no wear
marks and corresponds to the appearance of an unworn tool surface. The
chip is apparently not sliding against the surface of the coatings but on the
relatively thick inclusion layer. The wear of the tool is probably negligible.
Even more striking is the appearance of the flank surface (Fig. 9). Zone
E, where the AlzOa coating is completely consumed, constitutes almost the
whole contact area. In the same way as on the rake face, a thin, dark AlzOa
zone (F) indicates the transition from zone E to the unaffected tool surface
outside the contact area. Below zone F, where the contact between workpiece
and flank surface ends, small particles similar to sol.idified drops can be seen
along the whole cutting edge. Using EDX analysis, several Merent elements
can be detected in these particles: manganese, calcium and sulphur (from
11. 219
A Al,O, + TiN
8 TIC
C A'203
0 (Mn,Ca)S inclusion layer
Fig. 7. (a) Overdl view of the rake face. (b) Wear of the coatings close to the cutting edge.
the inclusions in the steel); aluminium and titanium (from the coatings on
the tool); chromium, silicon and (iron) (from the steel matrix). F’igure 9
indicates that a molten inclusion phase wets the work material-tool interface
during machining. The characteristic wear pattern with a completely consumed
A1203 coating close to the cutting edge and relatively thick inclusion layers
on the rake face appears after only approximately 2 min of machining. The
12. A
A’20, + TiN
E TiC
F
A',O,
Fig. 9. The flank face in the middle of the cutting edge.
AlaO coating is thus rapidly worn through. When the Tic coating next to
the cemented carbide is exposed, the wear rate of the coating decreases.
Based on extensive machining tests and tool wear studies for several
QT steels with different inclusion content, a number of different wear me-
chanisms have been identified [lo]. The most important wear mechanisms
are thought to be the following.
(A) Abrasion due to hard oxide inclusions. This mechanism is important
when machining untreated steels containing abrasive A120s inclusions.
(B) Dissolution of the coatings into adhered inclusion phases.
(C) DSusion-controlled wear.
For the particular steel investigated in the present work, mechanism B
is thought to be most important for the wear of the coatings. The abrasive
wear is thought to be of minor importance because of the low amount of
oxide inchrsions. The calcium ahuninates in the steel are relatively favourable
compared to AlsO3 inclusions from the abrasive wear point of view. Fur-
thermore, the extensive formation of relatively thick inclusion layers on the
rake face does probably reduce the importance of diSusion-controlled
wear.
Therefore, during turning of the caM.nn-treated steel, the wear of the
coatings close to the cutting edge is assumed to occur principally in the
following way.
(1) Adhesion of calcium-rich strIphide inclusions on the tool surface.
(2) The mehing temperature of the adhered sulphide decreases to the
temperat~e in the interface between tool and work material owing to
dissolution of other elements from the coatings into the inclusion layer.
13. 221
(3) Melting of the inclusion layer and wetting of the contact surfaces,
resulting in rapid dissolution of the coatings on the cemented carbide.
The wear mechanism is illustrated schematically in Fig. 10. This type
of wear is assumed to be active on both rake and flank surfaces of the tool.
The mixed sulphides with high calcium content are assumed to be very
important for the wear of the coatings even though they are relatively few.
The strength of the sulphides and the resistance to plastic deformation
increase when the calcium content in the inclusions increases. The abilie
of the adhered inclusions on the tool surface to withstand the contact load
during machining is also increased and therefore the inclusion layer is not
tom away from the tool surface. F’ure MnS and (~n,Ca)S with low calcium
content are heavily deformed on the contact surfaces and are easily removed
from the tool surface by the action of the work material.
The melting temperature for pure CaS is approximately 2400 “C [ 111.
Addition of manganese to the sulphide decreases the melting temperature
to a minimum at approximately 1500 “C for a composition of 72 mol.%
MnS. A similar influence of other elements present in the work material -
tool interface (aluminium, titanium, iron and others) can be expected. It
seems reasonable that the melting temperature of adhered CaS inclusion
layers can come down to the temperature on the too1 surface.
F’ig_10. Schematic view of the wear of the coatings close to the cutting edge. A, unworn tool.
B, adhesion of calcium rich sulphide inclusions. C, decrease in melting temperature of the
adhered sulphide due to ~olu~on of elements from the coatings into the inclusion layer.
D, melt&g of the inclusion layer, wetting of the contact surfaces and rapid ~olu~on of the
CO&IlgS.
14. 222
The decrease in melting temperature of the adhered inclusions is not
necessarily a diffusion-controlled process. Inclusion layer, coatings and steel
are in very intimate contact in the cutting zone. The different elements can
therefore be considered as already mixed on the contact surfaces owing to
the high contact loads and high temperatures. After initial wetting of the
contact surfaces, the dissolution of the coatings does probably proceed
rapidly. The mixture consisting of inclusions from the steel, dissolved coating
and work material is pressed out of the contact zone and follows the chip
or workpiece, or can be found on the rake or flank surfaces of the tool.
Adhered CaS has been found on all three types of coatings - Tic, AlaOs
and TiN. The proposed wear mechanism is assumed to be important for all
three coatings. However, the difference in wear rate is considerable between
different coatings. The wear rates have been estimated to be approximately
3 pm mix? in the AlaO coating and less than 1 pm min-’ in the Tic coating
for the machining conditions used. The tool wear studies indicate that turning
of a calcium-treated steel containing calcium-rich mixed sulphides using an
AlaO,-coated tool is unfavourable from the tool wear point of view.
8. Summary and conclusions
Tool wear, layer formation and inclusion behaviour have been studied
during turning of a calcium-treated quenched and tempered steel using coated
cemented carbide inserts. The deformation behaviour of different inclusion
types in the flow zone of the chip has been analysed using semiautomatic
image analysis. The following conclusions can be drawn.
(1) The deformation behavior-u in the flow zone is different for different
inclusion types. Manganese sulphides, MnS, and mixed sulphides, (Mn,Ca)S,
are plastically deformed. This is opposite to the behaviour of oxidic inclusions.
Calcium aluminates do not deform inthe flow zone even though the temperature
and shear strain are very high.
(2) The ability to deform plastically in the flow zone is not a prerequisite
for an inclusion type to contribute to the layer formation on the tool. Of
vital importance for tool wear and layer formation is the behaviour when
the inclusions are sliding against the tool surfaces.
(3) Manganese sulphides become extremely deformed in the flow zone
and in the chip -tool interface. No layers of MnS are formed on the tool
surface at high cutting speed (V= 208 m ruin-‘). The strength of the sulphide
is probably too low to withstand the contact load and the adhered sulphide
layers are tom away. The soft MnS inclusions do not cause any mechanical,
abrasive wear of the tools.
(4) Harder, calcium-containing inclusions such as (Mn,Ca)S and calcium
aluminate are continuously sliced off and smeared out during inclusion contact
with the tool. This behaviour is assumed to be favourable from the abrasive
wear point of view and to be a prerequisite for an inclusion type contributing
to layer formation.
15. 223
(5) Turning of the calcium-treated steel resulted in inclusion layers on
the tool surface. The differences in layer thickness and layer composition
between different areas were considerable. Thin CaS layers were adhered to
the coatings close to the cutting edge. Relatively thick (Mn,Ca)S layers were
formed further out on the rake surface.
(6) For the investigated calcium-treated steel the wear of coatings close
to the cutting edge is assumed to be mainly due to dissolution of the coatings
into adhered CaS inclusion layers. A relatively low amount of calcium-rich
sulphides in the steel is assumed to be important for the wear of the coatings.
(7) The results show that the inclusion layers on the tool surface do
not act as passive ditfusion barriers between steel and tool. Instead, the
inclusion layers interact with the coatings and the combination of inclusion
layer and coating composition are of importance for the wear rate. In particular,
the machining of a calcium-treated steel containing calcium-rich sulphides
using an AlsOa-coated tool is an unfavourable case.
Acknowledgments
This research work has been carried out with financial support from
Sandvik Coromant AB, Kloster Speedsteel AB, Ovako Steel AB, Bofors AB
and the National Swedish Board for Technical Development, which is gratefully
acknowledged. The authors would also like to thank the members of the
research committee, namely Rainer Lepp5nen (Ovako Steel AB), Bjijrn Olsson
(Sandvik Coromant AR), Lennart Sibeck (Bofors AB) and Henry Wisell (Kloster
Speedsteel AR), for valuable discussions.
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