The document presents two new concepts for efficiently joining metals to polymer composites without adhesives or fasteners: 1) Using a metal foam infiltrated with thermoplastic matrix to join carbon fiber composite to metal. 2) Using "Z-pins" anchored in metal and ultrasonically inserted into uncured composite prepreg. Prototype single and double lap shear joints were manufactured for each concept and tested. Initial results showed the metal foam joints withstood 5.6 kN and Z-pin joints withstood 31 kN before failure, demonstrating potential to transfer significant loads through these novel metal-composite joints.
Carburization is a thermo-chemical treatment generally employed to enhance the
surface (wear) properties of low carbon steels. The recent carburization studies also
focus considerable positive impact on bulk properties like tensile strength and
toughness. In view of these observations, the present study focuses on mechanical
properties and microstructure of carburized steels. Accordingly, the commercially
available three types of case hardenable steels like plain carbon (EN 3), alloy steels
with only ferrite stabilizer (20MnCr5) and with both ferrite (Cr) and austenite (Ni)
stabilizers (EN 353) were initially normalized to standardize the room temperature
structure before carburizing and machined to ASTM standards to prepare the
specimens. The machined specimens were gas carburized using carburizing furnace
for 2.5 mm case depth and furnace cooled. Tensile and hardness tests were conducted
before and after carburization. The plain carbon steel displayed slight reduction in
tensile strength and the steels with alloying elements increased the tensile strength
considerably. It was also found that Ni and Cr restrict the grain growth and increase
the strength of steel even in furnace cooled condition. Microstructure analysis of
carburized steels revealed markable impact on the type and distribution of room
temperature phases. The carbon content in the case was nearly 0.8 wt. % after
carburization and hardness increase in the surface ranges from 130 to 170% as that
of its original hardness. The combined effect of Ni and Cr also improves
hardenability.
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).
Carburization is a thermo-chemical treatment generally employed to enhance the
surface (wear) properties of low carbon steels. The recent carburization studies also
focus considerable positive impact on bulk properties like tensile strength and
toughness. In view of these observations, the present study focuses on mechanical
properties and microstructure of carburized steels. Accordingly, the commercially
available three types of case hardenable steels like plain carbon (EN 3), alloy steels
with only ferrite stabilizer (20MnCr5) and with both ferrite (Cr) and austenite (Ni)
stabilizers (EN 353) were initially normalized to standardize the room temperature
structure before carburizing and machined to ASTM standards to prepare the
specimens. The machined specimens were gas carburized using carburizing furnace
for 2.5 mm case depth and furnace cooled. Tensile and hardness tests were conducted
before and after carburization. The plain carbon steel displayed slight reduction in
tensile strength and the steels with alloying elements increased the tensile strength
considerably. It was also found that Ni and Cr restrict the grain growth and increase
the strength of steel even in furnace cooled condition. Microstructure analysis of
carburized steels revealed markable impact on the type and distribution of room
temperature phases. The carbon content in the case was nearly 0.8 wt. % after
carburization and hardness increase in the surface ranges from 130 to 170% as that
of its original hardness. The combined effect of Ni and Cr also improves
hardenability.
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).
Effects of Continuous Cooling On Impact and Micro Structural Properties of Lo...IJMER
Some mechanical properties and microstructural analysis were conducted on shielded
metal arc weldments of low carbon steels in some simulated environments. Specimens were prepared
and subjected to welding and continuous cooling at the same time at various positions. Results obtained
for impact strength using Charpy impact testing machine showed that impact strength of water cooled
samples were higher compared to salty water cooled samples. This is due to the increased formation of
martensitic structure and finer pearlite grains. The microstructure of the samples was studied using
photographic visual metallurgical microscope. For low cooling rate as in the air cooled sample, the
austenite was observed to transform into ferrite and pearlite. Ferrite is a body-centred cubic crystal
structure of iron alloys. For higher cooling rates of water and salt water cooled samples, low
temperature transformation products like bainite (an acicular microstructure which is not a phase) or
martensite (a very hard form of steel crystalline structure) were formed. The salt water cooled samples
had more martensite regions because of the increased cooling rate
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
Study of some Mechanical Properties of Galvanized 4140 SteelsIJAEMSJORNAL
The effect of three different galvanizing processes on the microstructure and tensile behavior and hardness of galvanized AISI 4140 steels was investigated. The thicknesses of the galvanized layers were measured as 34 μm, 90 μm and 140 μm for the electro galvanized, zinc-rich coated and hot dip galvanized AISI 4140 steels, respectively. No significant increase in tensile strength was observed with the galvanizing process. It was even observed that there was a decrease in tensile strength compared to the samples that were not galvanized. It is concluded that galvanizing processes is not effective in improving the tensile performance of AISI 4140 steels.
The International Journal of Engineering and Science (The IJES)theijes
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analysis of fumes emitted during hard facing of FCAW wiresIJAEMSJORNAL
Flux Cored Arc Welding (FCAW) wires are widely used for hard facing as they provide high deposition efficiency, wear resistance and faster speed rates than the solid wire used in Gas Metal Arc Welding process. Flux Cored Arc Welding process employs cored electrodes which contain the fluxing agents, metal powder, deoxidizers and Ferro alloys which contribute the fume emissions during the welding operation. The flux ingredients used vary based on the applications. An open-arc FCAW wire developed for high temperature wear resistance applications comprise borides, carbides of iron based alloy system. A high level of smoke is generated during welding with this wire which reduces the weld pool visibility. The research work is carried out to reduce the emission of fumes up to 70-80% (from present fume emission level) without affecting composition and wear behaviour of the alloy thereby making the wire environmental friendly.
Studying the Fatigue Properties Of Hardened For Carbon Steelijceronline
In this study, Medium carbon steel is one of the most important materials used in industrial applications especially it is used in applications exposed to fatigue stresses such as airplanes, automotive components and electrical engines industries. Medium carbon steels were prepared and the effect of hardening on hardening strength of medium carbon steel was studied, the flame hardening method was used at different speeds then fatigue test was done. The following results were obtained, first sample (none), second sample (3.5 mm/s), and third sample (1.75 mm /s) and forth sample (1.165 mm/s). It has been found that as the flaming speed increases, the fatigue strength of the material decreases. The fatigue test result at stress (407.44 N/mm2 ) was as follow: for the first sample the no. of cycles to failure was at (67511 rpm), for the second sample (95832 rpm), for the third sample (122565rpm) and for the fourth sample it was (134585 rpm).
Friction Stir Welding of steels: AReview PaperIOSR Journals
Friction Stir Welding (FSW) is a solid state joining process that can be applied to a number of
materials including aluminium, magnesium, copper and steels. A number of researches have been conducted in
Friction Stir Welding of steels and it is the focus of this paper to make a comprehensive review of the work that
has been done. Ultra-low carbon steels, low carbon steels, medium carbon steels, high carbon steels and ultrahigh
carbon steels have been considered and several aspects of FSW of steels have been outlined. These are
tools, mechanical properties and microstructure. It was determined that carbon content, welding speed as well
as rotational speed affect both mechanical properties and microstructure of the joint.
Development of WC-Feal Composite by Stir Casting MethodDr. Amarjeet Singh
In this paper author make an effort to develop a new
material for fulfill the need of present requirement. This
material is developed by the using of stir casting method. A
AMMC’s composite are developed to fulfill the need of present
requirements. This composite material is prepared by the use
of 3 metals. These metals are iron (Fe), aluminum (Al) and
tungsten carbide (WC).Thus this composite come under metal
matrix composite. This composite is WC – FeAl composite.
This is prepared by the use of stir casting method. The base
metals are iron and aluminum. These are having equal
quantity by weight. In this the sample is prepared by the
change the of percentage reinforcement. This is varying from
0 to 3%. A test is conduct to check their tensile strength as
well as compressive strength. By these test it is confirm that
with the increase the percentage of reinforcement in the
composite their tensile strength is decrease but their
compressive strength is increase.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of welding heat input on the microstructure of dissimilar metals: Inco...Mohamad Masaeli
Abstract
In dissimilar joining, the correct selection of filler metal and appropriate joining heat input is critical. In the current
study, two dissimilar alloys (Inconel 625, 316L stainless steel) and a super alloy of Inconel 625 were welded using
the tungsten arc method under inert gas protection. Welding was performed using three filler metals (Inconel 625, 82
and 309 L stainless steel) and three different heat inputs (1.5, 1.9, 2.3 kJ/mm) under the protection of argon gas.
Microstructures of different areas of welding joints were investigated under all welding conditions using optical
microscopy and a scanning electron microscope equipped with energy dispersive spectroscopy (EDS). The results
showed that all joining have a good continuity with no splits or discontinuity at the joint point. All filler metals
microstructures were observed in austenitic form with frozen dendrite structure. This investigation showed the
presence of an unadulterated region in some joining, and it became clear that this area increased with increased heat
input.
Effects of Continuous Cooling On Impact and Micro Structural Properties of Lo...IJMER
Some mechanical properties and microstructural analysis were conducted on shielded
metal arc weldments of low carbon steels in some simulated environments. Specimens were prepared
and subjected to welding and continuous cooling at the same time at various positions. Results obtained
for impact strength using Charpy impact testing machine showed that impact strength of water cooled
samples were higher compared to salty water cooled samples. This is due to the increased formation of
martensitic structure and finer pearlite grains. The microstructure of the samples was studied using
photographic visual metallurgical microscope. For low cooling rate as in the air cooled sample, the
austenite was observed to transform into ferrite and pearlite. Ferrite is a body-centred cubic crystal
structure of iron alloys. For higher cooling rates of water and salt water cooled samples, low
temperature transformation products like bainite (an acicular microstructure which is not a phase) or
martensite (a very hard form of steel crystalline structure) were formed. The salt water cooled samples
had more martensite regions because of the increased cooling rate
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
Study of some Mechanical Properties of Galvanized 4140 SteelsIJAEMSJORNAL
The effect of three different galvanizing processes on the microstructure and tensile behavior and hardness of galvanized AISI 4140 steels was investigated. The thicknesses of the galvanized layers were measured as 34 μm, 90 μm and 140 μm for the electro galvanized, zinc-rich coated and hot dip galvanized AISI 4140 steels, respectively. No significant increase in tensile strength was observed with the galvanizing process. It was even observed that there was a decrease in tensile strength compared to the samples that were not galvanized. It is concluded that galvanizing processes is not effective in improving the tensile performance of AISI 4140 steels.
The International Journal of Engineering and Science (The IJES)theijes
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.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Analysis of fumes emitted during hard facing of FCAW wiresIJAEMSJORNAL
Flux Cored Arc Welding (FCAW) wires are widely used for hard facing as they provide high deposition efficiency, wear resistance and faster speed rates than the solid wire used in Gas Metal Arc Welding process. Flux Cored Arc Welding process employs cored electrodes which contain the fluxing agents, metal powder, deoxidizers and Ferro alloys which contribute the fume emissions during the welding operation. The flux ingredients used vary based on the applications. An open-arc FCAW wire developed for high temperature wear resistance applications comprise borides, carbides of iron based alloy system. A high level of smoke is generated during welding with this wire which reduces the weld pool visibility. The research work is carried out to reduce the emission of fumes up to 70-80% (from present fume emission level) without affecting composition and wear behaviour of the alloy thereby making the wire environmental friendly.
Studying the Fatigue Properties Of Hardened For Carbon Steelijceronline
In this study, Medium carbon steel is one of the most important materials used in industrial applications especially it is used in applications exposed to fatigue stresses such as airplanes, automotive components and electrical engines industries. Medium carbon steels were prepared and the effect of hardening on hardening strength of medium carbon steel was studied, the flame hardening method was used at different speeds then fatigue test was done. The following results were obtained, first sample (none), second sample (3.5 mm/s), and third sample (1.75 mm /s) and forth sample (1.165 mm/s). It has been found that as the flaming speed increases, the fatigue strength of the material decreases. The fatigue test result at stress (407.44 N/mm2 ) was as follow: for the first sample the no. of cycles to failure was at (67511 rpm), for the second sample (95832 rpm), for the third sample (122565rpm) and for the fourth sample it was (134585 rpm).
Friction Stir Welding of steels: AReview PaperIOSR Journals
Friction Stir Welding (FSW) is a solid state joining process that can be applied to a number of
materials including aluminium, magnesium, copper and steels. A number of researches have been conducted in
Friction Stir Welding of steels and it is the focus of this paper to make a comprehensive review of the work that
has been done. Ultra-low carbon steels, low carbon steels, medium carbon steels, high carbon steels and ultrahigh
carbon steels have been considered and several aspects of FSW of steels have been outlined. These are
tools, mechanical properties and microstructure. It was determined that carbon content, welding speed as well
as rotational speed affect both mechanical properties and microstructure of the joint.
Development of WC-Feal Composite by Stir Casting MethodDr. Amarjeet Singh
In this paper author make an effort to develop a new
material for fulfill the need of present requirement. This
material is developed by the using of stir casting method. A
AMMC’s composite are developed to fulfill the need of present
requirements. This composite material is prepared by the use
of 3 metals. These metals are iron (Fe), aluminum (Al) and
tungsten carbide (WC).Thus this composite come under metal
matrix composite. This composite is WC – FeAl composite.
This is prepared by the use of stir casting method. The base
metals are iron and aluminum. These are having equal
quantity by weight. In this the sample is prepared by the
change the of percentage reinforcement. This is varying from
0 to 3%. A test is conduct to check their tensile strength as
well as compressive strength. By these test it is confirm that
with the increase the percentage of reinforcement in the
composite their tensile strength is decrease but their
compressive strength is increase.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of welding heat input on the microstructure of dissimilar metals: Inco...Mohamad Masaeli
Abstract
In dissimilar joining, the correct selection of filler metal and appropriate joining heat input is critical. In the current
study, two dissimilar alloys (Inconel 625, 316L stainless steel) and a super alloy of Inconel 625 were welded using
the tungsten arc method under inert gas protection. Welding was performed using three filler metals (Inconel 625, 82
and 309 L stainless steel) and three different heat inputs (1.5, 1.9, 2.3 kJ/mm) under the protection of argon gas.
Microstructures of different areas of welding joints were investigated under all welding conditions using optical
microscopy and a scanning electron microscope equipped with energy dispersive spectroscopy (EDS). The results
showed that all joining have a good continuity with no splits or discontinuity at the joint point. All filler metals
microstructures were observed in austenitic form with frozen dendrite structure. This investigation showed the
presence of an unadulterated region in some joining, and it became clear that this area increased with increased heat
input.
Design and Analysis of Bolted Joint in Composite LaminatedIJMER
In this work plate was designed for single and four bolted joint with two different materials such as mild steel and E-glass fiber. The aim of this work is to examine the distribution of tensile and crushing stress among the different bolts by changing material of plates and bolt. The bolted joints for mild steel plate and composite laminate were analyzed by using FEA. The result shows that tensile stress and crushing stress is less for composite laminate compare to mild steel .It is concluded that Weight reduction of structure is also achieved for e-glass fiber structure. The stress concentration was reduced in composite laminate bolted joints compare to mild steel so this will improve strength of structure.
REVIEW ON EFFECT OF HEAT INPUT ON TENSILE STRENGTH OF BUTT WELD JOINT USING M...ijiert bestjournal
Present work investigates the effect of heat input (controlled by welding current,welding voltage and welding speed) on tensile strength,micro-hardness and microstructure elements produced by shielded metal arc welding (SMAW). From the experimental res ults it was found that the increase in heat input affects the micro-constituents of base metal,and h eat affected zone (HAZ). Tensile strength decreases with increase in heat input and from scanning elect ron microscopy of tensile test fractured surfaces exhibited ductile & brittle failure. From micro har dness data values it was observed that hardness of material increases with increase in heat input in w eld pool and decreases in HAZ zone. Optical microscopy shows that smaller dendrite sizes and le sser inter-dendritic spacing were observed in the fusion zone at low heat input. And long dendrite si zes and large inter-dendritic spacing were observed in the fusion zone of the joint welded at high heat in put. Further it was observed from the optical micrographs that the extent of grain coarsening in the HAZ increases with increase in heat input. The welding heat input has a great influence on the wel dments properties. This paper describes the influen ce of welding heat input on the weld metal toughness of h igh-carbon steel surface welded joint .
Experimental and Finite Element Analysis of Single-V Groove Butt Weld on Weld...IJSRD
Gas Tungsten Arc Welding Process (GTAW) is widely used in fabrication of Aluminium and Aluminium Alloy material when precision is considered as a prime importance. Deformations in the object undergoing welding are one of the foremost problems encountered in the welding industry. Thus it is often required to study the factors which affect the deformations produced during welding to avoid errors in the geometry. Present investigation highlights Experimental and Finite Element Analysis of a Single-V Groove Butt Weld on Weld Pool Geometry of Aluminium Alloy Plate under Different Joint Parameters.Finite Element Method (FEM) has been employed to do the transient thermal and structural analysis of the assembly. The Finite Element Analysis has been done on ANSYS 14.5 Workbench. Number of factors is liable to produce effects in the job during the welding operation. Aim of this paper is the effect of welding parameters like as welding current, shielding gas flow rate and welding speed with mechanical Properties like tensile strength and hardness. After that finite element analysis for temperature distribution and distribution of the stresses in the welded Aluminium alloy plate. The results show that the larger the Welding current and smaller welding speed will lead to the maximum residual tensile stress. Therefore a residual stress will arise from the restraint position. The ultimate residual stress of weldment is determined by material yield strength at different temperature. The higher yield strength at different temperature has higher material residual stress. Because of its higher thermal conductivity, aluminium alloy test specimens have small temperature differential.
— Heat exchangers included in air conditioning systems for aircraft are produced by brazing stamped thin alloys sheets made of nickel-based alloys, Alloy 600 and Ni 201, or stainless steel, AISI 444. Separation metal sheets and locking bars of Alloy 625 are used to complete the system. The brazing filler metal, mainly composed of nickel, manganese, silicon and copper, is referred as BNi-8. In order to control brazing process, a good knowledge of both the brazing filler metal metallurgical behavior and of the interaction with the base metal is essential. The study of the brazing filler metal melting behavior in itself reveals that the melting point is highly dependent on the chemical composition and especially on silicon content. Microstructures analysis showed the presence of several phases with significant differences in terms of mechanical properties at a small scale which could induce local embrittlement. Interactions between the brazing filler metal and the different alloys constitutive of the assembly induce chemical composition evolutions related to the local configuration of the assembly. Dissolution and interdiffusion processes as well as chemical exchanges with the furnace environment occur. Finally, due to this set of phenomena, significant brazing defects can affect the mechanical integrity of the component.
Effect Of Process Parameters On Mechanical Properties Of Friction Stir.Welded...IJERA Editor
Friction Stir Welding (FSW) is an advance joining process for different similar and dissimilar materials. It is
commonly used for joining of Aluminum alloys. However it is necessary to overcome some challenges for its
wide-spread uses. Tool design and the selection of process parameters are critical issues in the usage of this
process. This study focuses on the process parameters that is required for producing effective friction stir
welding of two similar aluminum alloys (AA6101T6 to AA6101T6) and dissimilar Aluminum alloys
(AA6101T6 alloy to AA6351T6) . Three different tool diameters such as 20 mm, 25 mm and 30 mm with three
different tool rotational speeds such as 600 rpm, 800 rpm and 1200 rpm have been used to weld the joints. The
welded samples were tested for mechanical properties as well as microstructure. It was observed that 30 mm
tool gives better weld quality for friction stir welding of similar aluminum alloy but 25 mm tool with 1200 rpm
rotational speed gave satisfactory weld quality for friction stir welding of dissimilar aluminum alloys. It is one
of the important welding process that can adopted for welding of aluminum alloys with excellent mechanical
properties. The results were confirmed by further experiments.
. 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
1. Extended Abstract
New approaches to metal-composite joining
A Joesbury1
, D Ayre2
, I K Partridge2
, P Colegrove1
and S W Williams1
1
Welding Engineering Research Centre and 2
Composites Centre, Cranfield University,
Cranfield, Bedford, MK43 0AL
The contribution presents results from a new study that has the aim of achieving efficient
bonding between metals and polymer composites, without recourse to mechanical means
such as bolting and riveting and without the use of standard structural adhesives. Two
different design concepts for a highly loaded metal/composite lap-shear joint are proposed.
The new elements in this joining study are the use of metal foams infiltrated with
thermoplastic matrix, and exploitation of metallic ‘Z-pins’ anchored in a metallic adherend
and inserted into the uncured prepreg adherend by the use of an ultrasonic hammer.
Manufacturing issues and the mechanical performance of the prototype joints are evaluated.
The initial investigation demonstrates that significant loads can be transferred through these
novel metal-composite joints.
Keywords: joining, composite, CFRP, metal foam, PEEK, thermoplastic, dissimilar materials,
CMT, Z-pin
2. 1. Introduction
Fibre reinforced composites and metals are both widely used structural materials. These two
materials have significantly different properties, manufacturing processes, and in-service
behaviour, but are frequently used together within a single load carrying structure. Joining
methods between composites and metals almost exclusively rely on the joining techniques of
adhesive bonding, the use of mechanical fasteners, or a combination of the two. Due to the
differences between the two materials both adhesive bonding and mechanical fastening result
in significant penalties in terms of structural efficiency. This work investigates alternative
methods for joining composites to metals, with the aim of producing joints with greater
structural efficiency.
The infiltrated metal foam joint concept, joining a carbon fibre reinforced plastic (CFRP) to
metal, is illustrated in figure 1. This joint concept makes use of a polymer infused metal foam
to act as an intermediary material, which compensates for the differences in physical
properties between metal and composite materials1
, while making use of established metal-to-
metal and plastic-to-plastic joining methods. The thermoplastic chosen for this work was
PEEK.
Figure 1 Diagram of infiltrated metal foam joint concept
The anchored metallic ‘Z-Pins’ joint concept is illustrated in figure 2. This joint concept
incorporates aspects from both adhesive bonding and mechanical fastening. The pins,
attached by cold metal transfer welding (CMT), have a sufficiently small diameter such that
damage to the composite reinforcing fibres is significantly reduced when compared with
traditional fastening methods (e.g. rivets, bolts). When the pins are embedded into the
composite the joint benefits from an increased adhesive bonding areal density, composite
through thickness reinforcement at joining interface, and shear loading of metallic surface
features at the joining interface.
Figure 2 Diagram of anchored metallic ‘Z-Pin’ joint concept
2. Infiltrated metal foams
2.1. Materials and joint geometry
The infiltrated metal foam prototype joint consisted of a 3mm thick 304L stainless steel plate
joined to a 2mm thick laminate of unidirectional CFRP, APC-2, by the means of a PEEK
infused nickel metal foam intermediate material of 5mm thickness. A single lap shear joint of
40mm width with an overlap of 25mm was constructed.
Thermoplastic matrix CFRP to PEEK
infused metal foam: fusion joint
Metal plate to metal foam: laser
heating brazed joint
Pins encapsulated in CFRP
Metal plate with pins attached by
CMT-Pin welding process
3. 2.2. Manufacturing method
2.2.1. Laser brazing
The metal foam was first joined to
the braze filler metal are significantly
nickel metal foam2
, unlike direct
metal foam. The heat required to form the braze joint was provided by laser energy applied
indirectly, through the metal plate
2.2.2. Polymer infiltration and joining to composite
A heated platen press was used to raise t
subsequently apply a force to
constructed within the press to
piece of APC-2 carbon fibre composite and the PEEK as it was infused into the metal foam
This resulted in a single lap shear joint
metal foam and the brazed joint
Figure 3 Micrograph of PEEK infused nickel foam
3. Anchored metallic ‘Z
3.1. Materials and joint geometry
The anchored metallic ‘Z-Pin’
plate with the joint interface
steel pins. A regular array of 35 pins
then embedded into a quasi-isot
joint (DLS) of width 25mm and overlap of 30mm.
3.2. Manufacturing method
The Fronius developed CMT pin
interface area of the double lap shear joint. To improve
to methods used in previous work
an ultrasonic horn. The laminate
micrograph of the interaction between the pins and the quasi
4(b) shows the double lap shear joint after tensile failure.
fig.4(b), shows that several failure mechanisms are present: adhesion f
failure, pin necking, and pin shear fracture.
Manufacturing method
razing
The metal foam was first joined to a metal plate by brazing. Temperatures required to melt
significantly lower than the melting temperature of the
direct metal fusion joining temperatures which would destroy the
The heat required to form the braze joint was provided by laser energy applied
through the metal plate.
er infiltration and joining to composite
A heated platen press was used to raise the temperature of the PEEK to
push the PEEK melt into the porous metal foam.
constructed within the press to allow simultaneous formation of a fusion bond between the
2 carbon fibre composite and the PEEK as it was infused into the metal foam
This resulted in a single lap shear joint (SLS). Figure 3 shows a cross-section of
joint to metal plate.
Micrograph of PEEK infused nickel foam joined by silver
stainless steel plate.
Anchored metallic ‘Z-Pins’
Materials and joint geometry
Pin’ prototype joint consisted of a 3mm thick 304
the joint interface surface of the plate being structured with an array
A regular array of 35 pins was formed on both sides of the plate and
isotropic lay-up of M21/T700 prepreg to form a double lap shear
of width 25mm and overlap of 30mm.
Manufacturing method
The Fronius developed CMT pin-welding process4
was used to apply the array of
e lap shear joint. To improve the joint manufacturability compared
to methods used in previous work5
, these pins were then forced into the prepreg
he laminate was subsequently cured in an autoclave. Fig
micrograph of the interaction between the pins and the quasi-isotropic laminate and fig
4(b) shows the double lap shear joint after tensile failure. Visual inspection of the
that several failure mechanisms are present: adhesion f
and pin shear fracture.
Temperatures required to melt
lower than the melting temperature of the delicate
which would destroy the
The heat required to form the braze joint was provided by laser energy applied
the PEEK to 360ºC and
into the porous metal foam. A mould was
a fusion bond between the
2 carbon fibre composite and the PEEK as it was infused into the metal foam3
.
section of the infused
silver-copper braze to
304L stainless steel
an array of stainless
both sides of the plate and this plate was
to form a double lap shear
apply the array of pins to the
the joint manufacturability compared
the prepreg by the use of
Figure 4(a) shows a
isotropic laminate and figure
Visual inspection of the failed joint,
that several failure mechanisms are present: adhesion failure, laminate
4. (a) (b)
Figure 4 Micrograph of interaction between composite laminate and pins (a).
Photograph showing damage at failure of double lap shear tensile test (b).
4. Preliminary Mechanical Test Results
The lap joints constructed using resin infused metal foam and CMT-pins were tested in
tension to establish the load transfer capabilities and the mode of joint failure. The initial
findings are presented in table 1.
Table 1.
Results from mechanical testing of lap shear joints.
Joint Failure Load kN Failure Mode
Infiltrated Metal Foam
SLS
5.6 Progressive, initial failure at
brazed joint
Anchored metallic ‘Z-
Pins’ DLS
31.0 Progressive, initial adhesive
failure
Typical CRFP/metal
adhesive DLS5
21.5 Catastrophic adhesive failure
5. Conclusions
The work presented here is an overview of the initial investigations of prototype joints
constructed to investigate the feasibility of the infiltrated metal foam and anchored metallic
‘Z-Pin’ joining concepts. It has been demonstrated that manufacturability of these joints is
realistic and that the joints are capable of transferring a significant load. Further work is
currently in progress to investigate more fully the performance and characteristics of these
joining techniques.
Acknowledgements
The work presented here was funded through the Cranfield University IMRC.
References
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