The document provides information on metallography and microstructure analysis. It defines key terms like metallography, microstructure, phases, constituents, grains, grain boundaries, and grain size. It then discusses how to properly prepare metallographic specimens, including cutting, mounting, grinding, and polishing techniques. Finally, it provides examples of microstructures of various metals like aluminum, copper, steels, and superalloys revealed through different etching techniques.
1) Advances in metallographic techniques such as minimum area of contact cutting (MACC) and orbital cutting produce less damage to specimens during sectioning compared to traditional chop cutters.
2) Orbital cutting maintains a more constant pressure on the specimen compared to chop cutting, which varies pressure and increases heat generation.
3) Precision saws such as the IsoMet series provide versatility and optional features, allowing precise sectioning with minimal damage. Proper mounting and grinding/polishing techniques further minimize artifacts.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
This document contains summaries of the macrostructure and microstructure of various metal alloys and castings. It includes summaries of the dendritic structures, grain structures, phases present, and effects of heat treatments in materials like steels, aluminum alloys, copper alloys, nickel-based superalloys, and cast irons. Photographs at various magnifications accompany most summaries to illustrate the microstructural features.
This study examined the aluminizing behavior of low carbon steel with and without surface mechanical attrition treatment (SMAT) at lower temperatures. The following were observed for the SMAT sample compared to the untreated sample:
1) A much thicker iron aluminide compound layer formed with an enhanced growth kinetics of the η-Fe2Al5 phase at temperatures as low as 500-600°C.
2) The aluminide layer in the SMAT sample had a weakened crystallographic texture compared to the untreated sample.
3) The promoted aluminizing kinetics in the SMAT sample is attributed to increased diffusion and nucleation frequency in the nanostructured surface layer produced by SMAT.
Sensitization of Gold Dust in 430 Grade Stainless SteelIJAEMSJORNAL
'Gold dusting' is a surface defect that is sometimes observed on cold-rolled AISI type 430 stainless steel. Gold dusting is characterized by a sparkling appearance, which results from small flakes of metal on the cold rolled surface, the flakes are mostly elongated in the rolling direction. The processing steps include continuous casting, hot rolling, continuous annealing, and pickling. One possibility is that the flakes of metal are grains that had been undercut by intergranular corrosion such intergranular corrosion may occur during pickling after the annealing step (which itself follows hot rolling). If intergranular corrosion does occur during this pickling step, the intergranular cavities would be elongated by subsequent cold rolling; this can account for the observed morphology of gold dusting. If the steel has been sensitized, intergranular corrosion may occur during pickling. Pickling is commonly carried out by electrolytic descaling in a neutral sodium sulphate solution followed by immersion in a nitric acid/hydrofluoric acid bath. The sensitized type 430 stainless steel does, indeed, suffer intergranular corrosion in a nitric acid/hydrofluoric acid bath, while it is largely unaffected during electrolytic pickling. Hence, sensitization is a possible cause of gold dusting.
1) The document studies obtaining ultra fine grain sizes in plain C-Mn steels with 0.15-0.3% carbon through warm deformation processing.
2) Three new processing routes are developed involving heavy warm deformation at different temperatures followed by cooling or coiling to produce either pearlitic, bainitic ferrite 1, or bainitic ferrite 2 microstructures.
3) Lower deformation/coiling temperatures produce finer ferrite grains but more elongated aspect ratios, while pearlitic/bainitic ferrite grains are smaller and more equiaxed than pro-eutectoid ferrite grains.
(1) The document analyzes a steel bar that cracked during a bending test. (2) Microstructural examination revealed a martensitic surface zone with higher hardness than the ductile ferrite-pearlite core. (3) Chemical analysis found the steel to meet specifications. (4) The steel bar was likely overquenched during manufacturing, leading to a martensite area exceeding 30% and reduced ductility, causing cracks during bending.
1) Advances in metallographic techniques such as minimum area of contact cutting (MACC) and orbital cutting produce less damage to specimens during sectioning compared to traditional chop cutters.
2) Orbital cutting maintains a more constant pressure on the specimen compared to chop cutting, which varies pressure and increases heat generation.
3) Precision saws such as the IsoMet series provide versatility and optional features, allowing precise sectioning with minimal damage. Proper mounting and grinding/polishing techniques further minimize artifacts.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
Study on hardening mechanisms in aluminium alloysIJERA Editor
The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is
further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the
heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly,
highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several
characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180
oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing
(FSP) can be introduced to surface modification process and hardened the cast aluminium alloys. In this study,
hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present
task.
This document contains summaries of the macrostructure and microstructure of various metal alloys and castings. It includes summaries of the dendritic structures, grain structures, phases present, and effects of heat treatments in materials like steels, aluminum alloys, copper alloys, nickel-based superalloys, and cast irons. Photographs at various magnifications accompany most summaries to illustrate the microstructural features.
This study examined the aluminizing behavior of low carbon steel with and without surface mechanical attrition treatment (SMAT) at lower temperatures. The following were observed for the SMAT sample compared to the untreated sample:
1) A much thicker iron aluminide compound layer formed with an enhanced growth kinetics of the η-Fe2Al5 phase at temperatures as low as 500-600°C.
2) The aluminide layer in the SMAT sample had a weakened crystallographic texture compared to the untreated sample.
3) The promoted aluminizing kinetics in the SMAT sample is attributed to increased diffusion and nucleation frequency in the nanostructured surface layer produced by SMAT.
Sensitization of Gold Dust in 430 Grade Stainless SteelIJAEMSJORNAL
'Gold dusting' is a surface defect that is sometimes observed on cold-rolled AISI type 430 stainless steel. Gold dusting is characterized by a sparkling appearance, which results from small flakes of metal on the cold rolled surface, the flakes are mostly elongated in the rolling direction. The processing steps include continuous casting, hot rolling, continuous annealing, and pickling. One possibility is that the flakes of metal are grains that had been undercut by intergranular corrosion such intergranular corrosion may occur during pickling after the annealing step (which itself follows hot rolling). If intergranular corrosion does occur during this pickling step, the intergranular cavities would be elongated by subsequent cold rolling; this can account for the observed morphology of gold dusting. If the steel has been sensitized, intergranular corrosion may occur during pickling. Pickling is commonly carried out by electrolytic descaling in a neutral sodium sulphate solution followed by immersion in a nitric acid/hydrofluoric acid bath. The sensitized type 430 stainless steel does, indeed, suffer intergranular corrosion in a nitric acid/hydrofluoric acid bath, while it is largely unaffected during electrolytic pickling. Hence, sensitization is a possible cause of gold dusting.
1) The document studies obtaining ultra fine grain sizes in plain C-Mn steels with 0.15-0.3% carbon through warm deformation processing.
2) Three new processing routes are developed involving heavy warm deformation at different temperatures followed by cooling or coiling to produce either pearlitic, bainitic ferrite 1, or bainitic ferrite 2 microstructures.
3) Lower deformation/coiling temperatures produce finer ferrite grains but more elongated aspect ratios, while pearlitic/bainitic ferrite grains are smaller and more equiaxed than pro-eutectoid ferrite grains.
(1) The document analyzes a steel bar that cracked during a bending test. (2) Microstructural examination revealed a martensitic surface zone with higher hardness than the ductile ferrite-pearlite core. (3) Chemical analysis found the steel to meet specifications. (4) The steel bar was likely overquenched during manufacturing, leading to a martensite area exceeding 30% and reduced ductility, causing cracks during bending.
This document discusses inclusion control for clean steel production. It defines inclusions as non-metallic compounds that form separate phases in steel. Strict inclusion control is important for producing quality steel products. Inclusions are assessed and controlled by examining their source, shape, composition and distribution. Common inclusions include oxides, sulfides, and carbides. Modification techniques aim to make inclusions less harmful by modifying their shape, composition and dispersion in the steel matrix. Calcium additions are often used to modify alumina and manganese sulfide inclusions. Proper inclusion control is important at all stages of steelmaking and processing to achieve clean steel.
Manufacturing of Surface Composite Al6351/SIC Using Friction Stir ProcessingIJSRD
Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the most significant development in metal joining in a decade. Recently, friction stir processing (FSP) was developed for microstructural modification of metallic materials. In this study, SiC particles and Methanol paste were incorporated by using Friction Stir Processing (FSP) into the 6351 aluminum alloy to form particulate composite materials. Samples were subjected to traverse speeds of the FSP tool with and without Paste (SiC+ Methanol). Microstructural observations were carried out by employing optical microscopy of the modified surfaces. For the 100% overlapping, No. of passes caused grain modification in the processed zone.
The document provides guidelines for preparing metal specimens for microscopic examination. Key steps include carefully selecting and cutting a representative sample, mounting it, grinding it with successively finer grit paper to create a flat surface, polishing it to remove scratches, and sometimes etching it to reveal microstructural features. Proper preparation helps facilitate clear examination and accurate interpretation of grain structure, phases, inclusions and other microscopic characteristics of the material.
This document summarizes the failure analysis of a helical gear used in a steel mill reducer gearbox. Visual examination found two broken teeth with pitting on the contact side. Investigation found the gear material was a low alloy steel and fractography showed brittle fracture from excessive contact stress. The failure was caused by replacing the original motor with a more powerful one, increasing stress over 3 times higher than allowable for the gear material and leading to pitting, crack initiation and growth, and final fracture.
This document provides an overview of powder metallurgy and the production of metal powders. It discusses:
1) The powder metallurgy process which involves compacting metal powders into shapes and sintering them to form solid parts. Common metals used include iron, copper, aluminum, and titanium.
2) Methods for producing metal powders including atomization, reduction, electrolysis, the carbonyl process, and comminution. Particle size, shape, flow properties and density are also discussed.
3) The steps involved - powder production, blending, compaction, sintering, and finishing. Blending ensures uniformity while compaction forms the shape and increases strength.
The document discusses the powder metal process. It begins by providing an introduction to powder metallurgy, including its early uses and common applications today. The basic PM process consists of 5 steps: powder production, blending, compaction, sintering, and finishing operations. Several methods for producing metal powders are described, including atomization, chemical reduction, electrolytic deposition, mechanical comminution, and mechanical alloying. Key characteristics of metal powders like particle size, shape, chemistry, and flow properties are also covered. The document concludes with descriptions of the blending, compaction, sintering, and finishing stages of the PM process.
1) The study investigated the microstructure and mechanical properties of continuously cast iron products under different casting conditions and chemical compositions.
2) Key findings were that tensile strength, hardness, and pearlite content increased with higher additions of Cr, Cu, Sb and lower carbon equivalent. Higher Si/C ratio and lower solidification rate also decreased the zone of interdendritic graphite.
3) A structural nomograph was developed to show the effects of solidification rate and chemical composition on the microstructure of continuously cast iron.
Design and fabrication of spur gear using metal matix compositeRagava Rak
This document describes the design and fabrication of a spur gear using an aluminum-silicon carbide (Al-SiC) metal matrix composite. Key points include:
1) An Al-SiC composite with 7% SiC by weight was produced using stir casting. Processing parameters like temperature and stirring speed were investigated.
2) A spur gear was designed with a module of 4mm and power handling capacity of 10.1kw. The gear was fabricated using hobbing.
3) Experimental results showed the composite achieved highest strength when melt temperature was 800°C, allowing good particle wetting and minimal reaction. The composite material showed potential for use in power transmission gears.
The document presents a study on fabricating and characterizing an aluminum metal matrix composite reinforced with silicon carbide particles. The objectives are to fabricate the Al-SiC MMC, characterize its tensile strength and hardness properties, and determine optimal machining parameters for good surface finish. It discusses the composite materials, matrix, reinforcement, classification of composites, and metal matrix composites. It also details the properties of aluminum, silicon carbide, and aluminum silicon carbide composites. Methods of fabricating Al-SiC MMC including stir casting and characteristics like tensile testing, hardness testing, and machining tests are explained. Relevant literature on improving mechanical properties of Al-SiC composites is reviewed.
Edge effect in high speed slurry erosion wear tests of steels and elastomersNiko Ojala
While the slurry transportation via pumping is an increasingly viable alternative for the conventional fine
particle pumping, there are also many applications involving larger particles. However, the published studies
on slurry erosion have mainly been conducted with fine particle sizes. In this work, both fine and large
particle high speed slurry erosion of commercial wear resistant materials is studied.
The high speed slurry-pot wear tester was used with edge protected samples to simulate the wear conditions
in industrial slurry applications, such as tanks and pipelines. Two quenched wear resistant steels together
with natural rubber and polyurethane lining materials were tested, and the results were compared with the
results of the same materials tested without sample edge protection. The tests were performed using 15 m/s
speed, 45° and 90° sample angles, and 9 wt% and 33 wt% slurry concentrations with particle size ranging
from large 8/10 mm granite to fine 0.1/0.6 mm quartz.
With or without edge protection, the steel samples showed stable wear behavior, whereas the elastomers
gave notably inconsistent results in different test conditions. Steels exhibited better wear performance with
large particles and elastomers with fine particles. In general, the wear losses were 40 – 95 % lower without
edge wear, except for elastomers tested with fine quartz at the 45° sample angle, which yielded 25 – 75 %
higher weight losses when the sample edges were protected. With increasing abrasive size, the edge wear
becomes more dominant.
When possible, the full conference paper will be published at https://www.researchgate.net/publication/303881460_Edge_effect_in_high_speed_slurry_erosion_wear_tests_of_steels_and_elastomers
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.
Study on Processing and Mechanical Properties of nano SiCp reinforced AA7075theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
This document discusses friction stir processing (FSP), a technique for modifying the microstructure of metals near the surface. FSP uses a rotating tool to generate heat and plasticize the metal. As the tool traverses the material, it leaves behind a fine-grained microstructure. The document outlines the working principle of FSP and its applications, including fabricating surface composites, refining cast alloys, and producing superplasticity. FSP effectively improves mechanical properties like strength and ductility compared to the as-cast condition.
- Sol-gel coating was applied to stainless steel to improve its wear resistance. Alumina was deposited on AISI 304 stainless steel via dip coating and heat treatment.
- Characterization found the coating was smooth, homogeneous, and compact with higher hardness than the uncoated steel. Alumina peaks were detected via EDX.
- Pin-on-disk tests showed the coated steel had lower friction coefficients and less wear than the uncoated steel. The coated surface remained smooth at low speeds with no defects, while uncoated steel roughness increased after wear.
The document discusses developing cube texture orientation in pure iron through a novel warm rolling method. Warm rolling at temperatures between 500-800°C is proposed to align the cube faces of body-centered cubic iron crystals with the rolling surface, which could provide advantages for magnetic properties. Controlling the crystal orientation through elastic compliance during warm rolling aims to enhance magnetic flux density and reduce iron losses.
Preparation Of Specimen For Microscopic ExaminationPATEL DEEP
The document provides detailed steps for preparing metallographic specimens for microscopic examination, including:
1) Cutting a representative sample from the material being tested, mounting the sample, grinding it with progressively finer grit paper, and polishing it to a mirror finish.
2) Etching the polished sample to reveal microstructural features by selectively corroding the material, then washing and drying it.
3) The final prepared sample is then ready for examination under a microscope to study properties like grain size and phase distribution at different magnifications. Proper preparation is crucial to obtain accurate results without introduced artifacts.
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.
Powder metallurgy (P/M) is used to produce parts when other metalworking processes cannot be used due to high melting points or difficulty in machining. P/M involves producing metal powders, blending them with other powders, compacting the blended powder into a "green" part, sintering the part to bond the powders together, and finishing the part. Near 70% of P/M production is for automotive applications due to its ability to produce parts with good dimensional accuracy and controllable porosity.
The document discusses powder metallurgy, which involves producing metal parts from metal powders. The basic steps are powder production, blending/mixing, powder consolidation like die pressing, and sintering. Powder metallurgy allows production of parts from metals with high melting points or that are difficult to machine, and is commonly used for automotive applications. It provides good dimensional accuracy and control over porosity and properties.
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
Este documento describe los procesos de solidificación que ocurren en las piezas fundidas. Explica que durante la solidificación hay cambios volumétricos, segregaciones y la formación de macro y microestructuras. También describe cómo la estructura de granos depende del sistema de aleación, composición, temperatura de colada y tipo de molde. Finalmente, introduce conceptos como el módulo de enfriamiento y cómo este afecta el orden y velocidad de solidificación.
El documento describe el Análisis del Modo de Falla y sus Efectos (AMFE), una herramienta para identificar y prevenir fallas potenciales. Se desarrolló originalmente para la industria aeroespacial en los años 1970 y desde entonces se ha aplicado a una variedad de industrias. El AMFE involucra un análisis sistemático de un grupo multidisciplinario para detectar fallas potenciales, evaluar sus efectos, y determinar acciones para eliminar o reducir las probabilidades de falla.
This document discusses inclusion control for clean steel production. It defines inclusions as non-metallic compounds that form separate phases in steel. Strict inclusion control is important for producing quality steel products. Inclusions are assessed and controlled by examining their source, shape, composition and distribution. Common inclusions include oxides, sulfides, and carbides. Modification techniques aim to make inclusions less harmful by modifying their shape, composition and dispersion in the steel matrix. Calcium additions are often used to modify alumina and manganese sulfide inclusions. Proper inclusion control is important at all stages of steelmaking and processing to achieve clean steel.
Manufacturing of Surface Composite Al6351/SIC Using Friction Stir ProcessingIJSRD
Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the most significant development in metal joining in a decade. Recently, friction stir processing (FSP) was developed for microstructural modification of metallic materials. In this study, SiC particles and Methanol paste were incorporated by using Friction Stir Processing (FSP) into the 6351 aluminum alloy to form particulate composite materials. Samples were subjected to traverse speeds of the FSP tool with and without Paste (SiC+ Methanol). Microstructural observations were carried out by employing optical microscopy of the modified surfaces. For the 100% overlapping, No. of passes caused grain modification in the processed zone.
The document provides guidelines for preparing metal specimens for microscopic examination. Key steps include carefully selecting and cutting a representative sample, mounting it, grinding it with successively finer grit paper to create a flat surface, polishing it to remove scratches, and sometimes etching it to reveal microstructural features. Proper preparation helps facilitate clear examination and accurate interpretation of grain structure, phases, inclusions and other microscopic characteristics of the material.
This document summarizes the failure analysis of a helical gear used in a steel mill reducer gearbox. Visual examination found two broken teeth with pitting on the contact side. Investigation found the gear material was a low alloy steel and fractography showed brittle fracture from excessive contact stress. The failure was caused by replacing the original motor with a more powerful one, increasing stress over 3 times higher than allowable for the gear material and leading to pitting, crack initiation and growth, and final fracture.
This document provides an overview of powder metallurgy and the production of metal powders. It discusses:
1) The powder metallurgy process which involves compacting metal powders into shapes and sintering them to form solid parts. Common metals used include iron, copper, aluminum, and titanium.
2) Methods for producing metal powders including atomization, reduction, electrolysis, the carbonyl process, and comminution. Particle size, shape, flow properties and density are also discussed.
3) The steps involved - powder production, blending, compaction, sintering, and finishing. Blending ensures uniformity while compaction forms the shape and increases strength.
The document discusses the powder metal process. It begins by providing an introduction to powder metallurgy, including its early uses and common applications today. The basic PM process consists of 5 steps: powder production, blending, compaction, sintering, and finishing operations. Several methods for producing metal powders are described, including atomization, chemical reduction, electrolytic deposition, mechanical comminution, and mechanical alloying. Key characteristics of metal powders like particle size, shape, chemistry, and flow properties are also covered. The document concludes with descriptions of the blending, compaction, sintering, and finishing stages of the PM process.
1) The study investigated the microstructure and mechanical properties of continuously cast iron products under different casting conditions and chemical compositions.
2) Key findings were that tensile strength, hardness, and pearlite content increased with higher additions of Cr, Cu, Sb and lower carbon equivalent. Higher Si/C ratio and lower solidification rate also decreased the zone of interdendritic graphite.
3) A structural nomograph was developed to show the effects of solidification rate and chemical composition on the microstructure of continuously cast iron.
Design and fabrication of spur gear using metal matix compositeRagava Rak
This document describes the design and fabrication of a spur gear using an aluminum-silicon carbide (Al-SiC) metal matrix composite. Key points include:
1) An Al-SiC composite with 7% SiC by weight was produced using stir casting. Processing parameters like temperature and stirring speed were investigated.
2) A spur gear was designed with a module of 4mm and power handling capacity of 10.1kw. The gear was fabricated using hobbing.
3) Experimental results showed the composite achieved highest strength when melt temperature was 800°C, allowing good particle wetting and minimal reaction. The composite material showed potential for use in power transmission gears.
The document presents a study on fabricating and characterizing an aluminum metal matrix composite reinforced with silicon carbide particles. The objectives are to fabricate the Al-SiC MMC, characterize its tensile strength and hardness properties, and determine optimal machining parameters for good surface finish. It discusses the composite materials, matrix, reinforcement, classification of composites, and metal matrix composites. It also details the properties of aluminum, silicon carbide, and aluminum silicon carbide composites. Methods of fabricating Al-SiC MMC including stir casting and characteristics like tensile testing, hardness testing, and machining tests are explained. Relevant literature on improving mechanical properties of Al-SiC composites is reviewed.
Edge effect in high speed slurry erosion wear tests of steels and elastomersNiko Ojala
While the slurry transportation via pumping is an increasingly viable alternative for the conventional fine
particle pumping, there are also many applications involving larger particles. However, the published studies
on slurry erosion have mainly been conducted with fine particle sizes. In this work, both fine and large
particle high speed slurry erosion of commercial wear resistant materials is studied.
The high speed slurry-pot wear tester was used with edge protected samples to simulate the wear conditions
in industrial slurry applications, such as tanks and pipelines. Two quenched wear resistant steels together
with natural rubber and polyurethane lining materials were tested, and the results were compared with the
results of the same materials tested without sample edge protection. The tests were performed using 15 m/s
speed, 45° and 90° sample angles, and 9 wt% and 33 wt% slurry concentrations with particle size ranging
from large 8/10 mm granite to fine 0.1/0.6 mm quartz.
With or without edge protection, the steel samples showed stable wear behavior, whereas the elastomers
gave notably inconsistent results in different test conditions. Steels exhibited better wear performance with
large particles and elastomers with fine particles. In general, the wear losses were 40 – 95 % lower without
edge wear, except for elastomers tested with fine quartz at the 45° sample angle, which yielded 25 – 75 %
higher weight losses when the sample edges were protected. With increasing abrasive size, the edge wear
becomes more dominant.
When possible, the full conference paper will be published at https://www.researchgate.net/publication/303881460_Edge_effect_in_high_speed_slurry_erosion_wear_tests_of_steels_and_elastomers
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.
Study on Processing and Mechanical Properties of nano SiCp reinforced AA7075theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
This document discusses friction stir processing (FSP), a technique for modifying the microstructure of metals near the surface. FSP uses a rotating tool to generate heat and plasticize the metal. As the tool traverses the material, it leaves behind a fine-grained microstructure. The document outlines the working principle of FSP and its applications, including fabricating surface composites, refining cast alloys, and producing superplasticity. FSP effectively improves mechanical properties like strength and ductility compared to the as-cast condition.
- Sol-gel coating was applied to stainless steel to improve its wear resistance. Alumina was deposited on AISI 304 stainless steel via dip coating and heat treatment.
- Characterization found the coating was smooth, homogeneous, and compact with higher hardness than the uncoated steel. Alumina peaks were detected via EDX.
- Pin-on-disk tests showed the coated steel had lower friction coefficients and less wear than the uncoated steel. The coated surface remained smooth at low speeds with no defects, while uncoated steel roughness increased after wear.
The document discusses developing cube texture orientation in pure iron through a novel warm rolling method. Warm rolling at temperatures between 500-800°C is proposed to align the cube faces of body-centered cubic iron crystals with the rolling surface, which could provide advantages for magnetic properties. Controlling the crystal orientation through elastic compliance during warm rolling aims to enhance magnetic flux density and reduce iron losses.
Preparation Of Specimen For Microscopic ExaminationPATEL DEEP
The document provides detailed steps for preparing metallographic specimens for microscopic examination, including:
1) Cutting a representative sample from the material being tested, mounting the sample, grinding it with progressively finer grit paper, and polishing it to a mirror finish.
2) Etching the polished sample to reveal microstructural features by selectively corroding the material, then washing and drying it.
3) The final prepared sample is then ready for examination under a microscope to study properties like grain size and phase distribution at different magnifications. Proper preparation is crucial to obtain accurate results without introduced artifacts.
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.
Powder metallurgy (P/M) is used to produce parts when other metalworking processes cannot be used due to high melting points or difficulty in machining. P/M involves producing metal powders, blending them with other powders, compacting the blended powder into a "green" part, sintering the part to bond the powders together, and finishing the part. Near 70% of P/M production is for automotive applications due to its ability to produce parts with good dimensional accuracy and controllable porosity.
The document discusses powder metallurgy, which involves producing metal parts from metal powders. The basic steps are powder production, blending/mixing, powder consolidation like die pressing, and sintering. Powder metallurgy allows production of parts from metals with high melting points or that are difficult to machine, and is commonly used for automotive applications. It provides good dimensional accuracy and control over porosity and properties.
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
Este documento describe los procesos de solidificación que ocurren en las piezas fundidas. Explica que durante la solidificación hay cambios volumétricos, segregaciones y la formación de macro y microestructuras. También describe cómo la estructura de granos depende del sistema de aleación, composición, temperatura de colada y tipo de molde. Finalmente, introduce conceptos como el módulo de enfriamiento y cómo este afecta el orden y velocidad de solidificación.
El documento describe el Análisis del Modo de Falla y sus Efectos (AMFE), una herramienta para identificar y prevenir fallas potenciales. Se desarrolló originalmente para la industria aeroespacial en los años 1970 y desde entonces se ha aplicado a una variedad de industrias. El AMFE involucra un análisis sistemático de un grupo multidisciplinario para detectar fallas potenciales, evaluar sus efectos, y determinar acciones para eliminar o reducir las probabilidades de falla.
Las 5S es una práctica de calidad japonesa para el mantenimiento integral de una empresa que incluye la clasificación y organización de elementos en el lugar de trabajo, limpieza y mantenimiento de la higiene, y compromiso con la disciplina. Aplicar las 5S mejora la calidad, elimina tiempos muertos, reduce costos, aumenta la productividad, crea un mejor ambiente laboral, y genera mayores beneficios para la empresa y sus empleados.
El documento describe la historia de la calidad desde tiempos antiguos, cuando los constructores podían ser ejecutados por fallas en la calidad de las casas. También señala que la calidad total tuvo su origen en Japón y ahora es importante para todas las empresas. Explica que la calidad total debe comunicarse a los trabajadores, proveedores y clientes para que la empresa tenga éxito. Finalmente, destaca que una buena calidad reduce costos y racionaliza recursos.
1. El documento describe la historia de la calidad y el control estadístico desde épocas antiguas hasta el presente. Se destacan las contribuciones de pioneros como Shewart, Deming y Juran.
2. En las primeras etapas, la inspección era la principal estrategia para garantizar la calidad. Con la revolución industrial surgieron los primeros inspectores dedicados a detectar productos defectuosos.
3. En el siglo XX, Shewart introdujo las gráficas de control estadístico y el ciclo PHVA. Los j
Este documento trata sobre la gestión de la calidad. Define calidad como el conjunto de propiedades y características de un producto o servicio que le confieren su aptitud para satisfacer las necesidades del cliente. Explica diferentes modelos de calidad como el control de calidad, la garantía de calidad y la calidad total. Resalta la importancia de identificar las necesidades del cliente y establecer sistemas de gestión de calidad para mejorar continuamente la satisfacción del cliente.
Este documento explica el diagrama de Pareto, incluyendo su historia, definición, cómo se elabora y sus usos. El diagrama de Pareto es una herramienta gráfica que permite identificar los pocos problemas más importantes sobre los cuales concentrar los esfuerzos de mejora. Se basa en el principio de que el 20% de las causas generan el 80% de los efectos. El documento incluye ejemplos de diagramas de Pareto de causas y fenómenos.
Este documento introduce los conceptos fundamentales de la corrosión. Explica que la corrosión puede ser seca o húmeda, y describe varios tipos de corrosión localizada como por picaduras, en resquicios o galvánica. También cubre los costos económicos de la corrosión y métodos para proteger contra la corrosión.
El documento presenta información sobre diferentes temas relacionados con materiales e ingeniería de materiales. Se describen las propiedades y aplicaciones de varios metales y aleaciones como el acero, aleaciones de cobre, plomo, aluminio, magnesio y plata. También se discuten conceptos sobre la estructura cristalina de los metales, tratamientos térmicos, procesos de conformación y clasificación de plásticos.
El documento proporciona información sobre los sistemas integrados de gestión. Explica que un sistema integrado de gestión permite unificar diferentes sistemas de gestión de una organización, como calidad, medio ambiente y seguridad, bajo una sola base documental. Detalla algunos de los beneficios de este enfoque como facilitar la gestión y el mejoramiento continuo. Luego presenta los objetivos del sistema integrado de gestión del INVIMA, que incluyen incrementar competencias, satisfacer al ciudadano y cumplir la legislación.
Este documento describe diferentes tipos de fundiciones clasificadas según su microestructura. Incluye fundición blanca, gris, nodular y maleable. Explica que las fundiciones contienen hierro, carbono y silicio, y que el carbono puede encontrarse como cementita o grafito. También cubre los efectos de los elementos de aleación y las propiedades generales de las fundiciones.
Este documento describe los diferentes tipos de metales utilizados en ingeniería. Explica que los metales se clasifican en ferrosos, que contienen hierro, y no ferrosos, que no lo contienen. Dentro de los ferrosos se encuentran los aceros y hierros fundidos, mientras que los no ferrosos incluyen aleaciones de aluminio, cobre, zinc y magnesio. También describe los diagramas de fase y microestructura de los aceros, así como su designación y aplicaciones comunes.
El documento describe los diferentes mecanismos y etapas de eliminación del calor durante el proceso de temple de aceros, incluyendo los factores que afectan la velocidad de enfriamiento y la estructura resultante. También explica los diferentes medios y tratamientos térmicos de temple como austempering y martempering para lograr estructuras específicas.
Este documento describe los diferentes tratamientos térmicos y termoquímicos que se pueden aplicar a los aceros para modificar su estructura y mejorar sus propiedades mecánicas. Explica tratamientos como el temple, normalizado, recocido, cementación, nitruración y carbonitruración, indicando sus objetivos, procesos y efectos sobre las propiedades del acero.
Este documento describe diferentes tratamientos térmicos superficiales como la cementación, cianuración y nitruración. La cementación consiste en enriquecer la superficie del acero con carbono para luego templarla y obtener una capa exterior dura y una interior blanda. La cianuración utiliza baños de cianuro o gases para agregar carbono y nitrógeno a la superficie. La nitruración emplea amoníaco gaseoso para depositar nitrógeno y formar una capa dura de nitruros de hierro. Estos tratamientos permit
El documento presenta una lista de temas relacionados con metalurgia y materiales, incluyendo la manufactura de hierro y acero, tratamientos térmicos y termoquímicos, aceros aleados, aceros inoxidables, aceros para herramientas, metales no ferrosos como titanio, aluminio, cobre y sus aleaciones, magnesio, níquel, estaño y plomo, y aleaciones para cojinetes. También cubre temas sobre metales a altas y bajas temperaturas, metalurgia de polvos, desgaste y rep
Este documento trata sobre los conocimientos generales de materiales. Explica conceptos clave como estructuras atómicas, microestructuras, materiales compuestos y tecnología de materiales. También cubre temas como defectos en materiales, propiedades de los materiales metálicos, cerámicos y plásticos, y procesos de fabricación primaria y secundaria como fundición, laminación y forjado.
Este documento describe el diagrama de Ishikawa o diagrama causa-efecto. Fue creado por Kaoru Ishikawa en 1953 para agrupar y visualizar las razones subyacentes a un problema o resultado que se desea mejorar. Explica tres métodos para construir el diagrama: 6M, flujo de proceso y estratificación. También describe los pasos para construir un diagrama de Ishikawa y analizar las causas potenciales de un problema con el fin de desarrollar un plan de acción para mejorarlo.
Este documento explica cómo crear un diagrama de Ishikawa o diagrama causa-efecto para analizar los factores que contribuyen a un problema o evento. Describe los pasos para construir el diagrama, incluyendo identificar el problema, establecer categorías principales, identificar causas específicas y subcausas, y analizar el diagrama completo. El propósito es visualizar y comprender de manera holística todas las posibles razones subyacentes de un fenómeno.
Este documento describe los métodos de análisis de causa raíz (ACR) y análisis de modo y efecto de falla (PM) para identificar las causas de fallas en procesos. El ACR utiliza un enfoque disciplinado para determinar las causas físicas, humanas y latentes de incidentes, mientras que el PM estudia los mecanismos que producen anomalías. Ambos métodos buscan implementar acciones correctivas para mejorar la seguridad, confiabilidad y reducir costos. El documento también discute la relación entre A
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Generative AI Use cases applications solutions and implementation.pdfmahaffeycheryld
Generative AI solutions encompass a range of capabilities from content creation to complex problem-solving across industries. Implementing generative AI involves identifying specific business needs, developing tailored AI models using techniques like GANs and VAEs, and integrating these models into existing workflows. Data quality and continuous model refinement are crucial for effective implementation. Businesses must also consider ethical implications and ensure transparency in AI decision-making. Generative AI's implementation aims to enhance efficiency, creativity, and innovation by leveraging autonomous generation and sophisticated learning algorithms to meet diverse business challenges.
https://www.leewayhertz.com/generative-ai-use-cases-and-applications/
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
Home security is of paramount importance in today's world, where we rely more on technology, home
security is crucial. Using technology to make homes safer and easier to control from anywhere is
important. Home security is important for the occupant’s safety. In this paper, we came up with a low cost,
AI based model home security system. The system has a user-friendly interface, allowing users to start
model training and face detection with simple keyboard commands. Our goal is to introduce an innovative
home security system using facial recognition technology. Unlike traditional systems, this system trains
and saves images of friends and family members. The system scans this folder to recognize familiar faces
and provides real-time monitoring. If an unfamiliar face is detected, it promptly sends an email alert,
ensuring a proactive response to potential security threats.
Height and depth gauge linear metrology.pdfq30122000
Height gauges may also be used to measure the height of an object by using the underside of the scriber as the datum. The datum may be permanently fixed or the height gauge may have provision to adjust the scale, this is done by sliding the scale vertically along the body of the height gauge by turning a fine feed screw at the top of the gauge; then with the scriber set to the same level as the base, the scale can be matched to it. This adjustment allows different scribers or probes to be used, as well as adjusting for any errors in a damaged or resharpened probe.
Tools & Techniques for Commissioning and Maintaining PV Systems W-Animations ...Transcat
Join us for this solutions-based webinar on the tools and techniques for commissioning and maintaining PV Systems. In this session, we'll review the process of building and maintaining a solar array, starting with installation and commissioning, then reviewing operations and maintenance of the system. This course will review insulation resistance testing, I-V curve testing, earth-bond continuity, ground resistance testing, performance tests, visual inspections, ground and arc fault testing procedures, and power quality analysis.
Fluke Solar Application Specialist Will White is presenting on this engaging topic:
Will has worked in the renewable energy industry since 2005, first as an installer for a small east coast solar integrator before adding sales, design, and project management to his skillset. In 2022, Will joined Fluke as a solar application specialist, where he supports their renewable energy testing equipment like IV-curve tracers, electrical meters, and thermal imaging cameras. Experienced in wind power, solar thermal, energy storage, and all scales of PV, Will has primarily focused on residential and small commercial systems. He is passionate about implementing high-quality, code-compliant installation techniques.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
2. Metallography is the study of microstructure, how it is
produced by composition and processing control, and the
relationship between microstructure, mechanical and
physical properties, and performance or service behavior.
To examine the microstructure, we must prepare
specimens properly so that the true structure, free of
artifacts due to preparation, can be observed and
properly identified, measured and interpreted.
3. Microstructure is the structure of a suitably
prepare specimen as revealed by a microscope
Microstructure consists of phases and/or
constituents.
A phase is a physically homogeneous, mechanically
separable portion of a material system.
A constituent is a phase or combination of phases,
which occurs in a characteristic configuration in an
alloy microstructure.
4. Grains are individual crystals within a metal.
Most metals are polycrystalline, that is, made up of many
individual crystals, but some are “single crystals” and
have no internal grain boundaries.
Grain boundaries are interfaces separating adjacent
grains where the orientation of the crystal lattice changes
from that of one grain to that of the other. The orientation
difference is large. Sub-grain boundaries exhibit a small
misorientation across the boundary.
5. Grain size is the dimension of the grains or
crystals in a polycrystalline metal exclusive of
twinned regions and sub-grains, when present.
Although grains are three-dimensional in space,
the size is estimated on the two-dimensional
plane-of-polish for a large aggregate of grains
(to provide statistical precision).
6. 5/16 Sieve 4 Sieve
8 Sieve
14 Sieve
Separation of
grains by sieving
after liquid metal
embrittlement of
Brass in Hg
3.3 mm
3.3 mm
3.3 mm
3.3 mm
7. To see the true microstructure we generally will
cut a specimen from a larger section (the specimen
must be representative) in a manner to minimize
damage; encapsulate the specimen in a polymeric
resin; grain and polish the specimen with a
damage-free surface; etch the specimen with a
suitable reagent (non-cubic metals may be
examined with polarized light unetched); and
document the images.
8. Medium and large format Delta™ abrasive
saws with wheels 10 to 18 inch diameter.
9. With the chop cutter the contact area, when cutting a round bar, is very small
initially, increases to a maximum, then decreases to a point contact. Thus, the
pressure varies through the cut. This reduces cutting efficiency and increases heat
generation. Orbital cutting reduces this variation. When the wheel lifts out of the
cut, coolant flows into the cut which reduces sectioning damage.
10. Great versatility and a multitude of optional
features make IsoMet® precision saws one of the
labs best tools. A wide range of blades, both
consumable and non-consumable, are available.
11. Modern presses, such as the SimpliMet® family of presses, have built in
heating and cooling systems. Cooling a thermosetting polymer back to near
ambient temperature reduces or eliminates shrinkage gaps, which improves
edge retention and minimizes contamination and bleed out problems.
13. The decarburized surface of this heat treated specimen of 440A
stainless steel cannot be measured accurately due to rounding;
the specimen was not mounted (Fry’s Reagent).
14. Semi-automatic (left) or fully automatic (right) systems not only improve
productivity but they produce much higher quality specimens with better
edge retention and freedom from artifacts – consistently.
15. 8 and 10” (200 and 250 mm) 12” (300 mm)
• Z-Axis Removal Control; • Under-Bowl Cooling
• Head Speeds 30,40,50,60,150 rpm
• Complementary or Contra; • Fully Programmable
16. Magnetic disk systems introduce convenience in multiple-user labs while
reducing platen inventory.
18. Alumina suspensions are redefined by sol-gel MasterPrep alumina (0.05-µm
particle size). Unlike calcined alumina suspensions, MasterPrep suspensions
are totally free of agglomerates. It markedly outperforms all other alumina
abrasives and has none of the problems associated with colloidal silica.
19.
20. Surface deformation from abrasive sectioning (left side, see arrows) of
commercial purity (CP) Ti, ASTM F 67, Grade 2 (UNS R50400), annealed
at 1038 °C, revealed using modified Weck’s reagent and cross polarized
light plus sensitive tint. Original image at 100X. The magnification bar is
100 µm long. Mechanical twins can be seen along the top surface (see
vertical arrow) which may have been caused by the clamping pressure.
21. Sectioning damage at cut edges of fine silver (100% Ag) revealed by etching
with 10% NaCN and 10% ammonium persulfate.
22. Residual damage from shearing 14-karat gold (58% Au) revealed by etching
with 10% NaCN and H2O2 (30% conc).
23. Residual grinding damage in fine silver (100% Ag) revealed by etching with
10% NaCN and 10% ammonium persulfate.
25. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
paper
180, 240 or 320
(P180, P240, or P400)
SiC, water cooled
6 (27)
240 – 300
Comp.
Until plane
UltraPol™
9- m MetaDi®
Supreme diamond
suspension
6 (27)
120 – 150
Comp.
5:00
TriDent™
3- m MetaDi Supreme
diamond suspension
6 (27)
120 – 150
Comp.
4:00
ChemoMet
®
0.05- m MasterPrep™
alumina suspension
6 (27)
120 – 150
Contra*
2:00
Based on 1 ¼ mount size *Use contra only with low-speed heads (<100 rpm)
26. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
5 (22)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
5 (22)
150
Comp.
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
5 (22)
150
Comp.
4:00
TriDent cloth
1- m MetaDi Supreme
diamond paste
5 (22)
120
Comp.
2:00
MicroCloth pad
0.05- m MasterMet®
Colloidal silica
5 (22)
120
Contra
1:30
27. Equiaxed alpha grains at the surface of a super-pure (SP) aluminum specimen
etched with Barker’s reagent, 30 V dc, 2 min. Note the damage from sectioning
along the surface (top edge); (polarized light + sensitive tint, 50X).
28. As-cast 206 aluminum (Al – 4.4% Cu – 0.3% Mg – 0.3% Mn) tint etched
with Weck’s reagent and viewed with crossed polarized light plus a
sensitive tint filter. Magnification bar is 50 µm long.
29. Wrought 2024-F aluminum (Al – 4.4% Cu – 1.5% Mg – 0.6% Mn) bar (28.5
mm diam.) showing the grain structure and intermetallics. Magnification
bar is 200 µm long. Anodized with Barker’s reagent (30 V dc, 2 min.).
Transverse plane.
31. Weld Base
Microstructure of a friction stir weld in 2519 aluminum (Al – 5.8% Cu – 0.3% Mn
– 0.3% Mg – 0.06% Ti – 0.1% V – 0.15% Zr) etched with Weck’s reagent and
viewed with polarized light plus sensitive tint. Original at 100X. The magnification
bar is 100 µm long.
32. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
320- (P400) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol Cloth
6- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TexMet® 1500Pad
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
3:00
TriDent Cloth
1- m MetaDi Supreme
diamond suspension
6 (27)
120
Comp.
2:00
MicroCloth Pad
0.05- m MasterMet
Colloidal silica
5 (22)
120
Contra
2:00
33. Microstructure of hot extruded, cold worked and annealed (500 °C) high-
purity copper etched with klemms III and Beraha’s PbS tint etches and
viewed with polarized light plus sensitive tint, 46 HV.
Klemm’s III Beraha’s PbS
100 µm 100 µm
34. As-Cast, Klemm’s II Wrought, Beraha’s PbS
Microstructure of as-cast and hot extruded and cold drawn (interior)
phosphorous-deoxidized copper tint etched and viewed with
polarized light plus sensitive tint.
200 µm
100 µm
35. Bright Field Nomarski DIC, Bar is 100 µm
Microstructure of sand-cast Cu – 4% Sn etched with Beraha’s PbS tint etch
revealing the dendritic cast structure. 63 HV.
200 µm 100 µm
36. Cu–30% Zn, HE, CR 50%, Annl. 704 °C – 30 min.
Klemm’s III, Original at 50X Beraha’s PbS, Original at 50X
Microstructure of wrought cartridge brass, Cu – 30% Zn, cold reduced 50% and
annealed at 704 °C (1300 °F) – 30 min. producing a fully recrystallized, and
grown, equiaxed FCC grain structure with annealing twins. Polarized light and
sensitive tint.
37. 100 µm 100 µm
Bright Field Nomarski DIC
Microstructure of Muntz Metal, Cu – 40% Zn, heated to 716 °C (1320
°F), held 1 h and water quenched producing still more beta phase
(colored), of larger size, and with less preferred orientation. Nomarski
DIC of this specimen tint etched with Klemm’s I reagent reveals the
grain and twin structure in the un-etched alpha phase (not colored).
38. Wrought, solution annealed and aged beryllium copper, Cu – 1.8% Be –0.3% Co. Heat treatment: 790
°C (1454 °F), hold 1 h, oil quench, age at 315 °C (600 °F) for 2 h. Hardness 380 HV. Swab etched with
equal parts ammonium hydroxide and hydrogen peroxide (3% conc.). Polarized light brings out the
diffuse “criss-cross” markings due to the fine ’ precipitates. There is some over-aging at the grain
boundaries where can be found. Original at 200X. Crossed polars + sensitive tint.
39. 20 µm
Polarized Light Nomarski DIC
1 martensite formed in fcc alpha phase in a Cu – 26% Zn – 5% Al shape
memory alloy (both un-etched).
40. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
BuehlerHercules™ H
Rigid grinding disk
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
3:00
MicroCloth pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
1:30
41. Line Pipe Alloy Coated with Three Layers of Polymer for Protection from Sea
Water Corrosion (Klemm’s I reagent, polarized light).
42. Ferrite grains in lamination sheet steel revealed using Klemm’s I tint etch. This is
a duplex condition where there are much larger grains near the surface.
Magnification bar is 100 µm in length (polarized light plus sensitive tint).
Mount
43. Twinned austenitic grain structure of wrought, annealed Fe – 39% Ni color etched
with Beraha’s sulfamic acid solution (100 mL water, 3 g potassium metabisulfite, 2
g sulfamic acid) and viewed with polarized light plus sensitive tint, 100X.
44. Twinned austenitic grain structure of solution annealed, wrought Hadfield
manganese steel (Fe – 1.12% C – 12.7% Mn – 0.31% Si) tint etched with Beraha’s
sulfamic acid reagent (100 mL water, 3 g potassium metabisulfite and 2 g sulfamic
acid) and viewed with polarized light plus sensitive tint, 100X.
45. Upper bainite (blue and white) and as-quenched martensite (brown) in 5160 alloy steel (Fe
– 0.6% C - 0.85% Mn – 0.25% Si – 0.8% Cr) that was austenitized at 830 °C (1525 °F) for
30 min., isothermally held at 538 °C (1000 F°) for 30 sec to partially transform the
austenite, and then water quenched (untransformed austenite forms martensite). Etched
with aqueous 10% Na2S2O5.
46. Low-carbon, “lath” martensite in an over-austenitized specimen of AerMet 100 (Fe – 0.23% C – 13.4%
Co – 11.1% Ni – 3.1% Cr – 1.2% Mo). The grain size was coarsened by the heat treatment (1093 °C,
AC, age at 675 °C for 6 h, AC) making it easier to see the lath structure. Etched with aqueous 10%
sodium metabisulfite and viewed with polarized light plus sensitive tint. Original magnification was
100X. AerMet is a trademark of Carpenter Technology Corp., Reading, Pennsylvania.
47. Example of “butterfly” martensite (low carbon martensite) formed on the polished surface
of a specimen of High-Expansion 22-3 (Fe – 0.1% C – 0.5% Mn – 0.2% Si – 3.1% Cr – 22%
Ni) alloy steel when cooled to –73 °C. Unstable austenite transformed to martensite with its
characteristic shear which is visible on a free surface using Nomarski DIC ( not etched).
25 µm
48. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Contra
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Contra
5:00
ChemoMet pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
2:00
49. Microstructure of Custom Flo 302-HQ austenitic stainless steel (Fe - <0.08% C – 18% Cr –
9% Ni – 3.5% Cu) in the hot rolled and solution annealed condition after tint etching with
Beraha’s BI reagent. The structure is equiaxed, twinned FCC austenite. The faint vertical
lines are from alloy segregation (longitudinal direction is vertical). Viewed with polarized
light plus sensitive tint. The magnification bar is 100 µm long.
50. Microstructure of wrought 7-Mo duplex stainless steel (Fe - <0.1% C – 27.5% Cr –
4.5% Ni – 1.5% Mo) solution annealed and then aged 48 h at 816 °C to form sigma.
Electrolytic etching with aqueous 20% NaOH (3 V dc, 10 s) revealed the ferrite as
tan, the sigma orange, while the austenite was not colored. Magnification bar is 10
µm in length.
51. Dendritic microstructure of Alloy 718 in the as-cast condition after tint
etching with Beraha’s reagent. Note the white particles are delta phase.
The magnification bar is 200 µm long.
52. Microstructure of wrought, solution annealed and double aged (about 42 HRC)
Waspaloy, a nickel-based superalloy (Ni – 0.06% C – 19.5% Cr – 4.2% Mo – 13.5% Co
– 3% Ti – 1.35% Al – 0.07% Zr –0.005% B - <2% Fe) tint etched with Beraha’s BIV
reagent revealing twinned austenitic grains. Viewed in bright field. The magnification
bar is 100 µm long.
53. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TexMet 1500 pad
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
4:00
TriDent cloth
1- m MetaDi Supreme
diamond suspension
6 (27)
120
Comp.
3:00
ChemoMet pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
2:00
55. Microstructure of austempered ductile iron tint etched with Beraha’s CdS
reagent containing large graphite nodules (arrow), bainite (blue and
brown) and retained austenite (white) when viewed with polarized light
plus sensitive tint. Original at 500X.
56. As-cast NiHard cast iron (Fe – 2.98% C – 0.64% Mn – 0.85% Si – 4.4% Ni – 2.34% Cr)
containing cementite (white), retained austenite (light brown), manganese sulfides (gray
particles) and plate martensite “needles” (light blue and medium blue) after tint etching
with Beraha’s CdS reagent and viewing with polarized light plus sensitive tint, 1000X.
57. Surface Abrasive Load, lb. rpm Minutes
Waterproof
Discs
220-320-grit
(P240-P400) SiC
3 (13 N) 150-240
(comp.)
Until Plane
TexMet 1500
Pad
9-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
5
TexMet 1500
Pad
3-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
3
TexMet 1500
Pad
1-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
2
ChemoMet
Pad
MasterPrep Sol-Gel
Alumina
2 (9) 100-150
(comp.)
2
*Use water as the lubricant, but keep the surface relatively dry
Comp. = complementary ( both the head and platen rotating counterclockwise)
58. For 18-karat gold alloys, and similar highly noble
precious metals: it is necessary to use an attack-polish
agent in the MasterPrep alumina abrasive step. Mix 10
mL of the attack-polish solution with 50 mL of
MasterPrep alumina slurry. The attack-polish agent
can be: H2O2 (30% conc.), or aqueous 5-20% CrO3, or
aqueous 10% oxalic acid, etc.
59. Microstructure of as-cast pure ruthenium, as polished, viewed in polarized light
plus sensitive tint revealing a mixture of equiaxed and columnar HCP grains and
some small shrinkage cavities (black). The magnification bar is 200 µm long.
60. Bright Field Nomarski DIC
Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using
martensite formation to create a rippled effect (“spangles”) on the surface. The
specimen was polished, heated to 100 °C for 2 minutes, and quenched in water to
form martensite, which produces shear at the free surface. This roughness can be
seen using Nomarski DIC without etching. The criss-crossed pattern is produced by
forming martensite, polishing and then forming new martensite.
61. Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using martensite
formation to create a rippled effect (“spangles”) on the surface. The specimen was
polished, heated to 100 °C for 2 minutes, and quenched in water to form martensite,
which produces shear at the free surface. This roughness can be seen using Nomarski
DIC without etching. The criss-crossed pattern is produced by forming martensite,
polishing and then forming new martensite. The magnification bar is 50 µm long.
62. Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using
martensite formation to create a rippled effect (“spangles”) on the surface. The
specimen was polished, heated to 100 °C for 2 minutes, and quenched in water to form
martensite, which produces shear at the free surface. This roughness can be seen using
Nomarski DIC without etching. The criss-crossed pattern is produced by forming
martensite, polishing and then forming new martensite.
63. Microstructure of wrought sterling silver ( 92% Ag) revealed
by etching with equal parts of ammonium hydroxide and
hydrogen peroxide (3% conc.)
64. Microstructure of fine silver ( 100% Ag) revealed by etching with
10% NaCN and 10% ammonium persulfate.
65. Bright Field Polarized Light
14-karat gold (52% Au) prepared without attack polishing, etched with
equal parts of 10% NaCN and hydrogen peroxide (30% conc.) and viewed
with bright field and with polarized light.
66. Previous specimen of 14-karat gold examined with polarized light plus a
sensitive tint filter. The color effect comes from the surface roughness
created by the grain-contrast etch.
67. The 14-karat gold specimen after attack polishing and re-etching with
10% NaCN and H2O2 (30% conc.) revealing a “flat” etch.
68. 14-karat gold, attack polished and etched with equal parts of 10% NaCN
and H2O2 (30% conc.) and viewed with bright field and Nomarski DIC.
Bright Field Nomarski DIC
69. 18-karat gold (75% Au – 22% Ag – 3% Ni) after attack polishing and
etching with equal parts of 10% NaCN and H2O2 (30% conc.).
70. Bright Field Nomarski DIC
18-karat gold (75% Au – 22% Ag – 3% Ni) after attack polishing and
etching with equal parts of 10% NaCN and H2O2 (30% conc.) and
viewed with bright field and Nomarski DIC.
71. As-cast Paliney 7 (35% Pd – 30% Ag – 14% Cu – 10% Pt – 10% Au – 1%
Zn) etched with aqua regia revealing a dendritic structure.
72. Solution annealed and aged 44% Pd – 38% Ag – 1% Ni – 16% Cu
etched with equal parts of 10% NaCN and 10% ammonium
persulfate .
73. Solution annealed and aged 44% Pd – 38% Ag – 1% Ni – 16% Cu etched
with a 10 to 1 mix of HCl and HNO3. This etch brings up the grain
boundaries in the matrix phase. Note the lamellar nature of the second-phase
constituent.
74. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
Carbimet paper
320- (P400) grit SiC
Water cooled
4 (18)
240
Comp.
Until
plane
Ultra-Pol cloth
9- m Metadi Supreme
diamond suspension
4 (18)
150
Comp.
4:00
Texmet 1000 pad
3- m Metadi Supreme
diamond suspension
5 (22)
120
Comp.
4:00
Microcloth pad
0.05- m Masterprep
alumina suspension
6 (27)
120
Comp.
3:00
75. Microstructure of Resiten G7 glass silicone laminate composite viewed with
Nomarski DIC. The magnification bars are 100 and 50 µm long, respectively
(left and right).
76. Microstructure of a graphite-fabric reinforced polysulfone composite
viewed with cross polarized light plus sensitive tint. The magnification
bar is 100 µm long.
77. Microstructure of a fiberglass-reinforced polymer I beam viewed with
Nomarski DIC. The magnification bar is 20 µm long.
78.
79. Extensive mechanical twinning was observed in high-purity, electron-
beam melted zirconium after hot working and cold drawing. Viewed in
polarized light. Magnification bar is 100 µm long.
80. Microstructure of wrought pure hafnium, with an as-polished specimen viewed in
polarized light plus sensitive tint, revealing an equiaxed alpha HCP grain
structure. A few mechanical twins can be seen at the surface (yellow arrows). The
magnification bar is 100 µm long.
Surface
Mount
81. Microstructure of a W – 27% Cu powder metallurgy composite material after hot
isostatic pressing. The specimen was etched with Klemm’s III for 20 seconds and
imaged with bright field. The magnification bar is 20 µm long.
82. Microstructure of Zn – 0.1% Ti – 0.1% Cu hot rolled to 6 mm thickness, in the
as-polished condition (left), using polarized light, revealing elongated HCP
grains containing mechanical twins. Some fine precipitates are present in the
grain boundaries but are not clearly revealed. For comparison, the structure on
the right is shown after etching with the Palmerton reagent and viewing with
polarized light plus sensitive tint). The magnification bars are 50 µm long.
83. Microstructure of Cd – 20% Bi in the as-cast condition, unetched, viewed with
polarized light (slightly off the crossed position) plus sensitive tint revealing
cadmium dendrites of various orientation. The interdendritic consituent is a
eutectic of Cd and Bi, but is too fine to resolve at this magnification. The
magnification bar is 200 µm long.
84. Microstructure of wrought 99.98% magnesium etched with the acetic-
picral reagent and viewed with crossed polarized light plus a sensitive
tint filter. The magnification bars are 200 and 100 µm long, left and
right, respectively.
85. Microstructure of as-cast Mg – 2.5% rare earth elements - -2.11% Zn –
0.64% Zr revealed using the acetic-picral reagent and viewed with polarized
light plus a sensitive tint filter. The magnification bars are 100 and 50 µm in
length, left and right, respectively. A few mechanical twins can be seen.
86. Surface Abrasive/Size Load,
lbs./(N)
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
paper
320-grit (P400)
watercooled
6 (27) 240
Contra or Comp.
Until Plane
UltraPol Cloth
(psa)
9-µm MetaDi
Supreme
6 (27) 150
Contra
10:00
MicroCloth
pad
(psa)
0.05-µm
MasterPrep (1
part H2O2, 30%
conc, to 5 parts
alumina)
6 (27) 150
Contra
(head <100 rpm)
10:00
Do not use contra in step 3 if the head rotates >100 rpm, as the abrasive will be
splattered all over the room
87. Microstructure of CP Ti, ASTM F 67, Grade 2 (UNS R50400; specimen was in
the as-rolled condition) prepared using the three-step method and viewed with
polarized light to reveal the grain structure. Magnification bar is 100 µm long.
Note the mechanical twins in the grains (arrows).
88. Microstructure of CP Ti, ASTM F 67, Grade 2 (UNS R50400; specimen in the as-
rolled condition) prepared using the three-step method (previous slide) followed
by a 20 minute vibratory polish, and viewed with crossed polarized light to reveal
the grain structure. Original image at 100X. Magnification bar is 100 µm long.
Note the deformation twins (arrows).
89. Microstructure of a Ti- 0.2% Pd alloy (UNS R52400) prepared using the three-
step method and viewed with crossed polarized light to reveal an equiaxed alpha
grain structure. Magnification bar is 100 µm long. The area at the left shows
heavy deformation twinning (arrow) from sectioning (the cut edge is off the field of
view to the left).
90. Microstructure of as-cast Ti – 6% Al – 4% V prepared using the three-step
method, etched with modified Weck’s reagent, and viewed with polarized
light to reveal a coarse “basket-weave” alpha/beta matrix structure. The
boundaries of several former beta grains can be seen. Magnification bar is
200 µm long.
91. Microstructure of CP titanium containing SiC fibers prepared using the three-step
method for titanium. The structure was viewed with Nomarski DIC to reveal the
minor height differences. The magnification bar is 100 µm long.