The research work is carried out on the study of tribological property of aluminium based metal matrix composite material, which is fabricated by using sol-gel technique. The composite material is prepared through liquid metallurgy method by using varying percentage of Alumina and aluminium and fixed percentage of copper 4.2%. Test sample billet is fabricated through casting method and has been examined the different mechanical behaviour such as Vickers Hardness Number, Ultimate Tensile Strength, 0.2% Proof Stress, etc.
From the study, it has been observed that with increase in the alumina content in matrix the ductility of composite show a contrary effect. The Pin-On-Disc test is used to evaluate the tribological property wear for composite material and it is observered that tendency of wear rate has improved. The weight losses of the specimen are measured and wear and friction characteristics are calculated with respect to time. Depth of wear track, sliding speed, bearing load friction coefficient and wear volume have been shown large sensitivity to the applied normal load and the testing time (or sliding distance). The XRD and SEM analysis are used to analyse the wear debris and track; and silent conclusion has been drawn
FRACTOGRAPHY OF CRYOGENIC CHILL CASTED ASTM A 494 M GRADE NICKEL ALLOY METAL ...IAEME Publication
ASTM A 494 M grade Ni–Garnet composites containing four different weight percentages 3%, 6%,9% and 12% of Garnet samples have been fabricated by using cryogenically cooled copper chill stir
casting method. Effects of volume percent of Garnet particles on tensile strength, and fracture surfacesof Nickel Garnet composites have been investigated. The highest tensile strength was achieved in the specimen containing 9 Wt. % garnet produced with 25 mm chill thickness which shows an increase of14% in comparison to the no chill cast reinforced alloy. Microscopic investigations of fracture surfacesrevealed that fracture in a brittle manner with little or no necking happening. By increasing garnetcontent and chill thickness, the composites fracture goes in a more severely brittle manner. The fracturebehavior of the composites was altered significantly by the presence of garnet particles and the crack
propagation through the matrix and the reinforcing particle clusters resulted in the final fracture.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This work deals with fabricating or producing magnesium based metal matrix composite and then studying its mechanical and tribological properties such as microstructure, tensile strength, impact strength and wear behavior of produced test specimen. In the present study a modest attempt has been made to develop magnesium based MMCs with reinforcing material, with an objective to develop a conventional low cast method of producing MMCs and to obtain homogeneous dispersion of reinforced material. To achieve this objective stir casting technique has been adopted. An Alloy similar to commercially available composition of AZ31 and SiC, Al2O3 has been chosen as matrix and reinforcing material respectively. Experiment has been conducted by varying weight fraction of 3% SiC and 1% Al2O3 & 1% SiC and 3% Al2O3 in matrix metal. The result shown that tensile strength, impact strength, wear resistance is good in matrix metal as compared to used weight compositions of SiC and Al2O3 in the composites.
Effect of Milling Time on Al-Fe-Cr-20 Wt. % Al2O3composite Prepared Through B...IJERA Editor
One of the main challenges towards achieving a homogeneous distribution of the ceramic phase in the metal matrix composites is agglomeration of the reinforcement particles. Mechanical alloying is among the most important processing techniques used for manufacturing of metal matrix composites (MMCs).An attempt was made to synthesize Al-Fe-Cr-Al2O3composites synthesized through mechanical alloying. Al2O3 is used as reinforcement. Ethanol (5 wt. %) has been used as a process control agent (PCA). Mechanical alloying is carried out in a conventional ball mill using stainless steel grinding media at 115 rpm in the argon environment for 5h, 10h and 15h. The ball to powder weight ratio was maintained at 20:1. The characterization of the ball milled powder was followed by scanning electron microscopy (SEM). Showed the formation of a homogeneous phase for all compositions after milling for 15 h. XRD patterns were recorded for the milled powders, and analyzed using Williamson–Hall method and Scherrer’s equation to determine the lattice strain and grain size.EDX is performed to check the contamination of composites during the mechanical alloying.XRD is used to study structural evolution of synthesized aluminium composite. Effect of milling time is investigated on synthesized Al-Fe-Cr-20 wt. % Al2O3 composites.
FRACTOGRAPHY OF CRYOGENIC CHILL CASTED ASTM A 494 M GRADE NICKEL ALLOY METAL ...IAEME Publication
ASTM A 494 M grade Ni–Garnet composites containing four different weight percentages 3%, 6%,9% and 12% of Garnet samples have been fabricated by using cryogenically cooled copper chill stir
casting method. Effects of volume percent of Garnet particles on tensile strength, and fracture surfacesof Nickel Garnet composites have been investigated. The highest tensile strength was achieved in the specimen containing 9 Wt. % garnet produced with 25 mm chill thickness which shows an increase of14% in comparison to the no chill cast reinforced alloy. Microscopic investigations of fracture surfacesrevealed that fracture in a brittle manner with little or no necking happening. By increasing garnetcontent and chill thickness, the composites fracture goes in a more severely brittle manner. The fracturebehavior of the composites was altered significantly by the presence of garnet particles and the crack
propagation through the matrix and the reinforcing particle clusters resulted in the final fracture.
A Study on Mechanical and Tribological Properties of Magnesium Alloy AZ31 Rei...ijsrd.com
This work deals with fabricating or producing magnesium based metal matrix composite and then studying its mechanical and tribological properties such as microstructure, tensile strength, impact strength and wear behavior of produced test specimen. In the present study a modest attempt has been made to develop magnesium based MMCs with reinforcing material, with an objective to develop a conventional low cast method of producing MMCs and to obtain homogeneous dispersion of reinforced material. To achieve this objective stir casting technique has been adopted. An Alloy similar to commercially available composition of AZ31 and SiC, Al2O3 has been chosen as matrix and reinforcing material respectively. Experiment has been conducted by varying weight fraction of 3% SiC and 1% Al2O3 & 1% SiC and 3% Al2O3 in matrix metal. The result shown that tensile strength, impact strength, wear resistance is good in matrix metal as compared to used weight compositions of SiC and Al2O3 in the composites.
Effect of Milling Time on Al-Fe-Cr-20 Wt. % Al2O3composite Prepared Through B...IJERA Editor
One of the main challenges towards achieving a homogeneous distribution of the ceramic phase in the metal matrix composites is agglomeration of the reinforcement particles. Mechanical alloying is among the most important processing techniques used for manufacturing of metal matrix composites (MMCs).An attempt was made to synthesize Al-Fe-Cr-Al2O3composites synthesized through mechanical alloying. Al2O3 is used as reinforcement. Ethanol (5 wt. %) has been used as a process control agent (PCA). Mechanical alloying is carried out in a conventional ball mill using stainless steel grinding media at 115 rpm in the argon environment for 5h, 10h and 15h. The ball to powder weight ratio was maintained at 20:1. The characterization of the ball milled powder was followed by scanning electron microscopy (SEM). Showed the formation of a homogeneous phase for all compositions after milling for 15 h. XRD patterns were recorded for the milled powders, and analyzed using Williamson–Hall method and Scherrer’s equation to determine the lattice strain and grain size.EDX is performed to check the contamination of composites during the mechanical alloying.XRD is used to study structural evolution of synthesized aluminium composite. Effect of milling time is investigated on synthesized Al-Fe-Cr-20 wt. % Al2O3 composites.
Aluminum-lithium alloys used in the aerospace industry as structural components
and strengthened by age-hardening. This study aims to improve properties of Al-Li
alloys such as strength, behavior hot rolling and addition element, i.e. Mg and Cu to
this alloy. Several tests were carried out to evaluate the performance of alloy, such as
hardness, tensile, and microstructure by OP, SEM and XRD. Result showed that
addition 3.2% Cu to base alloy improve strength from (62MPa) to (78MPa) when
aging at 175°C.and improve hardness from (97.3 Hv) to (119.79Hv) At the same
temperature. But the improvement is great when addition 0.6% Mg to base alloy
improve tensile strength from (62MPa) to (124MPa) at the same time improved
hardness from (119.79Hv) to (152.96Hv) at the same temperature.
STRUCTURE PROPERTY CORRELATION OF MODIFIED Al-Mg ALLOYS FOR AEROSPACE APPLICA...sivanagaraju chittelu
Making a new metal for Aerospace applications which is made of many components .Major metals are Aluminium and Magnesium.Checking its structures and properties .
Experimental Investigation on Mechanical Properties of Hybrid Metal Matrix Co...IJMERJOURNAL
ABSTRACT : In the present investigation, the study on mechanical properties of Aluminum Hybrid Matrix Composites (AMCs) reinforced with alumina (Al2O3), silicon carbide (Sic) and graphite (Gr) particles. Al6063 alloy is used as the matrix material with varying the reinforcement of alumina at fixed quantity of 5 wt% SiC and 5 wt% of graphite. The composites were fabricated by stir casting equipment methodology with controlled speed and feed parameters. Hardness is measured by using Brinell hardness equipment and tensile properties were measured by using universal testing machine and it is compared with aluminum alloy. There was a great advancement in hardness and tensile properties by changing the compositions. The Sic and Al2O3 resulted in improving the hardness and density of their respective composites. Further, the changing the compositions of these reinforcements contributed in increased hardness and density of the composites
MICROSTRUCTURAL CHARACTERIZATION AND HOT EROSION BEHAVIOR OF CRC-NICR COATED ...IAEME Publication
Erosion behavior of the High Velocity Oxygen Fuel (HVOF) deposited CrC - NiCr coating on stainless steel was evaluated. Th e solid particle erosion stu dy was conducted using an air jet erosion test rig at a velocity 60m/sec and impingement angle 60 ° , 75 ° and 90 ° , on HVOF spray coated steel at 600 ° C. Microstructure, chemical composition, phases present in the coating on the steel substrate was studied by using Scanning Electron Microscope (SEM) and X - Ray Diffraction method. The Hardness is gradually increasing with increasing content of Cr 3 C 2 particles in all three samples. The erosion mechanism of coatings was also discussed and erosion rate is maximum at impingement angle 75 °
Studies on Al8081-B4C Metal Matrix Composites Fabricated by Stir Casting MethodIJMER
Aluminium MMCs are preferred in the fields of aerospace, military, automotive, marine and
in many other domestic applications. In the present work, an attempt has been made to develop and
study the, Mechanical properties of Al-8081/B4C reinforced aluminium metal matrix composites. The
composite was prepared by using Liquid Metallurgy Route (Stir Casting Technique). Liquid state has
some important advantages such as better matrix particle bonding, easier control of matrix structure,
simplicity, low cost of processing, nearer to net shape and wide selection of material. Al-8081 alloy
was taken as the base matrix to which B4C particulates are used as reinforcements. Al8081-B4C
composites were prepared by varying weight percentage of B4C i.e 0 to 6 %, in steps of two. The
objective is to study the effect of B4C particulates on mechanical properties such as ultimate tensile
strength, yield strength and hardness of Al8081 alloy composites. The results of this study revealed
that, as the B4C content was increased, there were significant increases in the ultimate tensile strength,
yield strength and hardness in the composites as compared to the base matrix
Investigation of Mechanical Behavior of Aluminium Alloys Before and After Wor...dbpublications
The ever increasing demand from aerospace industries and automotive industries to manufacture components which are lighter and stronger than conventional steel has prompted the significant usage of aluminium alloys. This research work involves the investigation of mechanical properties in aluminium alloys before and after work hardening. The alloy is work hardened using cold forging process. The major alloying elements used in the aluminium alloy are manganese, magnesium and silicon. The aluminium alloy ingots are prepared through gravity casting. After the ingots are air cooled to room temperature, they are work hardened using cold forging method where the ingots are forged at room temperature. The cold forged aluminium alloys are then subjected to tensile tests, wear tests, hardness tests and microstructure analysis using optical Scanning Electron Microscope (SEM). The material properties achieved are compared with the alloys properties that have not been subjected to work hardening. The expected outcome is to achieve a work hardened aluminium alloy that exhibits excellent mechanical properties which can be best suited for numerous industrial manufacturing requirements. Better ideal properties such as formability, weldability, increased hardness and wear resistance are expected from the cold forged alloys.
A Study on Mechanical Properties of Fly Ash and Alumina Reinforced Aluminium ...IOSR Journals
The results of an experimental investigation of the mechanical properties of fly ash and Alumina
reinforced aluminium alloy (LM25) composites samples, processed by stir casting route are reported in this
paper. Three sets of composites with constant weight fraction of fly ash (particle size of 3-100 μm) and
Al2O3(particle size of 150 μm) with different wt% were used. Composite samples have the reinforcement weight
fractions of constant 3% fly Ash and varying %wt of 5, 10 and 15% Al2O3 . The main mechanical properties
studied were the tensile strength,ductilityimpact strength & hardness. Unreinforced LM25 samples were also
tested for the same properties. It was found that the tensile strength & hardness of the aluminium alloy (Lm25)
composites increases with the increase in %wt of Al2O3 upto certain limit. in addition of more amount of
reinforcement the Tensile strength decrease due to poor wettability of the reinforced material with metal
aluminium matrix .And the charpy test shows decrease in impact load absorption with increase in %weight
reinforcement.The Microstructure study of the samples indicated near uniform distribution of the fly ash and
Al2O3 particles in the matrix. LM25 alloy is mainly used where good mechanical properties are required in
castings of a shape or dimensions requiring an alloy of excellent castability in order to achieve the desired
standard of soundness.The alloy is also used where resistance to corrosion is an important consideration
particularly where highstrength is also required.
Wear Properties of Thixoformed Al-5.7Si-2Cu-0.3Mg Aluminium AlloyDr. Manal Abdullatif
Earlier work has shown that Al-5.7Si-2Cu-0.3Mg aluminium alloy is suitable for
thixoforming process. Here, the dry sliding wear behaviour of the alloy, in the as-cast and
thixoformed conditions were investigated. The cooling slope technique was used to produce the alloy
with globular microstructure for the thixoforming process. Both the thixoformed and cast samples
were subjected to T6 heat treatments prior to the wear tests. The tests were carried out using a
pin-on-disc tribometer, against a hardened M2 tool steel disc of 62 HRC at different loads, under dry
sliding conditions at fixed sliding speed and sliding distance of 1 m.s–1 and 5 km respectively. The
microstructural response, worn surfaces was thoroughly and carefully examined using various
methods such as scanning electron microscopy, energy dispersive spectroscopy, and differential
scanning calorimetry. The density of the heat treated thixoformed alloys showed significant increase
in the hardness property, among others, due to its reduced porosity. Their wear test results also
observed that the weight loss of materials increase with an increase in the input load and the sliding
distance for all samples. However, the as-cast alloy displayed higher wear rate compared with the
thixoformed alloys. In general, the wear mechanisms showed a mixture of abrasive, oxidative and
delamination wear (mild wear) at low applied loads and mainly an adhesive (severe wear) at high
applied loads.
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.
. 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
Investigation on the Rate of Solidification and Mould Heating in the Casting ...IOSR Journals
Abstract: The quality of casting in the foundry can be measured by the rate at which solidification of the
molten metal takes place, which is consequent upon the rate the mould, is able to dissipate the heat of
solidification to the surroundings. The faster or slower the heat removal process during solidification the
structure of the grains formed by the casting is either finer of coarser. An experimental investigation was
carried out to compare the rate of solidification of commercially pure aluminium in metallic moulds. The rate at
which solidification occurred was compared with the rate at which the mould absorbed and dissipates heat. The
experiments conducted recorded the temperature fields at different casting location and that of the moulds
respectively. The results showed that there is a direct relation of the rate of heat absorption by the mould and
the rate of solidification in metallic moulds.
Keywords – Aluminium, casting, heat, mould, solidification, temperature.
Effect of Sintering Temperature on Mechanical Properties of Aluminum Compositesijtsrd
Using Al, Al2O3 and SiC, different types of composites have been prepared in this experiment. Green compacts of Al composites were made at a compressing load of 1 ton and 2 ton respectively. These compacts were sintered at two different sintering temperatures of 400 °C and 450 °C in an oxygen free environment using muffle furnace for one hour followed by annealing process which took 12 hours. Sintered compacts were then sintered to micro structural examination and mechanical properties evaluation. Higher hardness has been attained for the composites containing 2.5 SiC. Attempts have been made to describe the influence of sintering temperature on the microstructure and properties of Al Al2O3 SiC composites. Samples are prepared of 100 Al, 97.5 Al 2.5 Al2O3, 92.5 Al 7.5 Al2O3, 95 Al 2.5 Al2O3 – 2.5 SiC, 92.5 Al 5 Al2O3 – 2.5 SiC, 95 Al – 5 Al2O3. The main objective of this experiment is to determine the factors that can increase hardness of Al composites. Mohd Quasim Khan ""Effect of Sintering Temperature on Mechanical Properties of Aluminum Composites"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25073.pdf
Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/25073/effect-of-sintering-temperature-on-mechanical-properties-of-aluminum-composites/mohd-quasim-khan
Aluminum-lithium alloys used in the aerospace industry as structural components
and strengthened by age-hardening. This study aims to improve properties of Al-Li
alloys such as strength, behavior hot rolling and addition element, i.e. Mg and Cu to
this alloy. Several tests were carried out to evaluate the performance of alloy, such as
hardness, tensile, and microstructure by OP, SEM and XRD. Result showed that
addition 3.2% Cu to base alloy improve strength from (62MPa) to (78MPa) when
aging at 175°C.and improve hardness from (97.3 Hv) to (119.79Hv) At the same
temperature. But the improvement is great when addition 0.6% Mg to base alloy
improve tensile strength from (62MPa) to (124MPa) at the same time improved
hardness from (119.79Hv) to (152.96Hv) at the same temperature.
STRUCTURE PROPERTY CORRELATION OF MODIFIED Al-Mg ALLOYS FOR AEROSPACE APPLICA...sivanagaraju chittelu
Making a new metal for Aerospace applications which is made of many components .Major metals are Aluminium and Magnesium.Checking its structures and properties .
Experimental Investigation on Mechanical Properties of Hybrid Metal Matrix Co...IJMERJOURNAL
ABSTRACT : In the present investigation, the study on mechanical properties of Aluminum Hybrid Matrix Composites (AMCs) reinforced with alumina (Al2O3), silicon carbide (Sic) and graphite (Gr) particles. Al6063 alloy is used as the matrix material with varying the reinforcement of alumina at fixed quantity of 5 wt% SiC and 5 wt% of graphite. The composites were fabricated by stir casting equipment methodology with controlled speed and feed parameters. Hardness is measured by using Brinell hardness equipment and tensile properties were measured by using universal testing machine and it is compared with aluminum alloy. There was a great advancement in hardness and tensile properties by changing the compositions. The Sic and Al2O3 resulted in improving the hardness and density of their respective composites. Further, the changing the compositions of these reinforcements contributed in increased hardness and density of the composites
MICROSTRUCTURAL CHARACTERIZATION AND HOT EROSION BEHAVIOR OF CRC-NICR COATED ...IAEME Publication
Erosion behavior of the High Velocity Oxygen Fuel (HVOF) deposited CrC - NiCr coating on stainless steel was evaluated. Th e solid particle erosion stu dy was conducted using an air jet erosion test rig at a velocity 60m/sec and impingement angle 60 ° , 75 ° and 90 ° , on HVOF spray coated steel at 600 ° C. Microstructure, chemical composition, phases present in the coating on the steel substrate was studied by using Scanning Electron Microscope (SEM) and X - Ray Diffraction method. The Hardness is gradually increasing with increasing content of Cr 3 C 2 particles in all three samples. The erosion mechanism of coatings was also discussed and erosion rate is maximum at impingement angle 75 °
Studies on Al8081-B4C Metal Matrix Composites Fabricated by Stir Casting MethodIJMER
Aluminium MMCs are preferred in the fields of aerospace, military, automotive, marine and
in many other domestic applications. In the present work, an attempt has been made to develop and
study the, Mechanical properties of Al-8081/B4C reinforced aluminium metal matrix composites. The
composite was prepared by using Liquid Metallurgy Route (Stir Casting Technique). Liquid state has
some important advantages such as better matrix particle bonding, easier control of matrix structure,
simplicity, low cost of processing, nearer to net shape and wide selection of material. Al-8081 alloy
was taken as the base matrix to which B4C particulates are used as reinforcements. Al8081-B4C
composites were prepared by varying weight percentage of B4C i.e 0 to 6 %, in steps of two. The
objective is to study the effect of B4C particulates on mechanical properties such as ultimate tensile
strength, yield strength and hardness of Al8081 alloy composites. The results of this study revealed
that, as the B4C content was increased, there were significant increases in the ultimate tensile strength,
yield strength and hardness in the composites as compared to the base matrix
Investigation of Mechanical Behavior of Aluminium Alloys Before and After Wor...dbpublications
The ever increasing demand from aerospace industries and automotive industries to manufacture components which are lighter and stronger than conventional steel has prompted the significant usage of aluminium alloys. This research work involves the investigation of mechanical properties in aluminium alloys before and after work hardening. The alloy is work hardened using cold forging process. The major alloying elements used in the aluminium alloy are manganese, magnesium and silicon. The aluminium alloy ingots are prepared through gravity casting. After the ingots are air cooled to room temperature, they are work hardened using cold forging method where the ingots are forged at room temperature. The cold forged aluminium alloys are then subjected to tensile tests, wear tests, hardness tests and microstructure analysis using optical Scanning Electron Microscope (SEM). The material properties achieved are compared with the alloys properties that have not been subjected to work hardening. The expected outcome is to achieve a work hardened aluminium alloy that exhibits excellent mechanical properties which can be best suited for numerous industrial manufacturing requirements. Better ideal properties such as formability, weldability, increased hardness and wear resistance are expected from the cold forged alloys.
A Study on Mechanical Properties of Fly Ash and Alumina Reinforced Aluminium ...IOSR Journals
The results of an experimental investigation of the mechanical properties of fly ash and Alumina
reinforced aluminium alloy (LM25) composites samples, processed by stir casting route are reported in this
paper. Three sets of composites with constant weight fraction of fly ash (particle size of 3-100 μm) and
Al2O3(particle size of 150 μm) with different wt% were used. Composite samples have the reinforcement weight
fractions of constant 3% fly Ash and varying %wt of 5, 10 and 15% Al2O3 . The main mechanical properties
studied were the tensile strength,ductilityimpact strength & hardness. Unreinforced LM25 samples were also
tested for the same properties. It was found that the tensile strength & hardness of the aluminium alloy (Lm25)
composites increases with the increase in %wt of Al2O3 upto certain limit. in addition of more amount of
reinforcement the Tensile strength decrease due to poor wettability of the reinforced material with metal
aluminium matrix .And the charpy test shows decrease in impact load absorption with increase in %weight
reinforcement.The Microstructure study of the samples indicated near uniform distribution of the fly ash and
Al2O3 particles in the matrix. LM25 alloy is mainly used where good mechanical properties are required in
castings of a shape or dimensions requiring an alloy of excellent castability in order to achieve the desired
standard of soundness.The alloy is also used where resistance to corrosion is an important consideration
particularly where highstrength is also required.
Wear Properties of Thixoformed Al-5.7Si-2Cu-0.3Mg Aluminium AlloyDr. Manal Abdullatif
Earlier work has shown that Al-5.7Si-2Cu-0.3Mg aluminium alloy is suitable for
thixoforming process. Here, the dry sliding wear behaviour of the alloy, in the as-cast and
thixoformed conditions were investigated. The cooling slope technique was used to produce the alloy
with globular microstructure for the thixoforming process. Both the thixoformed and cast samples
were subjected to T6 heat treatments prior to the wear tests. The tests were carried out using a
pin-on-disc tribometer, against a hardened M2 tool steel disc of 62 HRC at different loads, under dry
sliding conditions at fixed sliding speed and sliding distance of 1 m.s–1 and 5 km respectively. The
microstructural response, worn surfaces was thoroughly and carefully examined using various
methods such as scanning electron microscopy, energy dispersive spectroscopy, and differential
scanning calorimetry. The density of the heat treated thixoformed alloys showed significant increase
in the hardness property, among others, due to its reduced porosity. Their wear test results also
observed that the weight loss of materials increase with an increase in the input load and the sliding
distance for all samples. However, the as-cast alloy displayed higher wear rate compared with the
thixoformed alloys. In general, the wear mechanisms showed a mixture of abrasive, oxidative and
delamination wear (mild wear) at low applied loads and mainly an adhesive (severe wear) at high
applied loads.
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.
. 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
Investigation on the Rate of Solidification and Mould Heating in the Casting ...IOSR Journals
Abstract: The quality of casting in the foundry can be measured by the rate at which solidification of the
molten metal takes place, which is consequent upon the rate the mould, is able to dissipate the heat of
solidification to the surroundings. The faster or slower the heat removal process during solidification the
structure of the grains formed by the casting is either finer of coarser. An experimental investigation was
carried out to compare the rate of solidification of commercially pure aluminium in metallic moulds. The rate at
which solidification occurred was compared with the rate at which the mould absorbed and dissipates heat. The
experiments conducted recorded the temperature fields at different casting location and that of the moulds
respectively. The results showed that there is a direct relation of the rate of heat absorption by the mould and
the rate of solidification in metallic moulds.
Keywords – Aluminium, casting, heat, mould, solidification, temperature.
Effect of Sintering Temperature on Mechanical Properties of Aluminum Compositesijtsrd
Using Al, Al2O3 and SiC, different types of composites have been prepared in this experiment. Green compacts of Al composites were made at a compressing load of 1 ton and 2 ton respectively. These compacts were sintered at two different sintering temperatures of 400 °C and 450 °C in an oxygen free environment using muffle furnace for one hour followed by annealing process which took 12 hours. Sintered compacts were then sintered to micro structural examination and mechanical properties evaluation. Higher hardness has been attained for the composites containing 2.5 SiC. Attempts have been made to describe the influence of sintering temperature on the microstructure and properties of Al Al2O3 SiC composites. Samples are prepared of 100 Al, 97.5 Al 2.5 Al2O3, 92.5 Al 7.5 Al2O3, 95 Al 2.5 Al2O3 – 2.5 SiC, 92.5 Al 5 Al2O3 – 2.5 SiC, 95 Al – 5 Al2O3. The main objective of this experiment is to determine the factors that can increase hardness of Al composites. Mohd Quasim Khan ""Effect of Sintering Temperature on Mechanical Properties of Aluminum Composites"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd25073.pdf
Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/25073/effect-of-sintering-temperature-on-mechanical-properties-of-aluminum-composites/mohd-quasim-khan
Development of Model for Quality Costing in a Medium Scale Industry-A Case StudyIOSR Journals
Abstract: Quality c o s t s pl ay s vi tal rol e in improving productivity. These costs are typically
categorized into costs of prevention, appraisal, internal and external failure. Like other activities of
business, quality costs can be programmed, budgeted, measured and analyzed to attain the objective of
better quality at lower cost. Quality costs is the basis by which investments in quality programs may be
evaluated in terms of cost improvement , profit enhancement and other benefits for plants and companies
from these programs. The cost of quality is an increasingly important issue in the debates over quality.
There was a mistaken notion that achievement of better quality requires higher costs. It was the myth that
prevented many Indian companies to invest more on quality cost related programs. In this article the
authors made an attempt to identify the different types of quality costs in a medium scale industry because
the small and medium scale industries pay very little attention towards finding and developing a system for
knowing & optimizing the cost of achieving quality. A model is proposed to identify the different quality
costs in a medium scale industry and is further implemented. It has been found some quality costs are more critical and require greater attention.
Key words: Quality costs, Quality management, Pareto analysis, Model for optimization
Ensemble Empirical Mode Decomposition: An adaptive method for noise reduction IOSR Journals
Empirical mode decomposition (EMD), a data analysis technique, is used to denoise non-stationary
and non-linear processes. The method does not require any pre & post processing of signal and use of any
specified basis functions. But EMD suffers from a problem called mode mixing. So to overcome this problem a
new method known as Ensemble Empirical mode decomposition (EEMD) has been introduced. The presented
paper gives the detail of EEMD and its application in various fields. EEMD is a time–space analysis method, in
which the added white noise is averaged out with sufficient number of trials; and the averaging process results
in only the component of the signal (original data). EEMD is a truly noise-assisted data analysis (NADA)
method and represents a substantial improvement over the original EMD.
Prevention of Selective Jamming Attacks by Using Packet Hiding MethodsIOSR Journals
Abstract: The open nature of the wireless medium leaves it too weak to intentional interference attacks,
typically defined as jamming. This intentional interference with wireless transmissions can be used as a launch
pad for mounting Denial-of-Service attacks on wireless networks. Typically, jamming has been introduced
under an external threat model. However, intruders with internal knowledge of protocol specifications and
network secrets can launch low-effort jamming attacks that are difficult to detect and counter. In this work, we
address the problem of selective jamming attacks in wireless networks. In these attacks, the hacker is active only
for a short period of time, selectively targeting messages of high importance. We demonstrate the advantages of
selective jamming in terms of network performance degradation and hacker effort by presenting two case
studies; a selective attack on TCP and one on routing. We show that selective jamming attacks can be
forwarded by performing real-time packet classification at the physical layer. To reduce these attacks, we
develop three schemes that prevent real-time packet classification by combining cryptographic primitives with
physical-layer attributes. We analyze the security of the proposed methods and evaluate their computational and
communication overhead.
A study of selected biomechanical variables as a factor of hitting performanc...IOSR Journals
Abstract: The modern age of sports is the excellence, so in every sports perfection and purification of skill has
got its immense importance. Biomechanics is an applied form of mechanics and consequently the method used
to investigate it must be derived from those of mechanics. Biomechanics aim to explain the mechanics of life.
Sports biomechanics have also generated other efforts at improving athletic performance in different games and
sports; it is helpful to minimize sports injuries through both identifying dangerous practice and designing safer
equipment and apparel. The purpose of this study was to investigate the relationship of selected biomechanical
variables with the hitting performance in softball.
Keywords: Biomechanical Variable, Centre of gravity, Evaluation of technique, Performance, Softball Hitting
CFD Simulation of Swirling Effect in S-Shaped Diffusing Duct by Swirl Angle o...IOSR Journals
Abstract: The present study involves the CFD analysis for the prediction of swirl effect on the characteristics
of a steady, incompressible flow through an S-shaped diffusing duct BY KEEPING SWIRL ANGLE OF 10˚. The
curved diffuser considered in the present case has S-shaped diffusing duct having an area ratio of 1.9, length of
300 mm and turning angle of 22.5°/22.5°. The static pressure, total pressure, velocity and turbulence intensity
were accounted. The improvement is observed for both, clockwise and anti-clockwise swirl, the improvement
being higher for clockwise swirl. Flow uniformity at the exit is more uniform for clockwise swirl at the inlet.
Keywords: Curved diffusers, intake ducts, swirling flow, secondary flows, pressure recovery
WEAR STUDIES ON THE HEAT TREATED AL6061-μSIC AND AL6061-NSIC METAL MATRIX COM...IAEME Publication
Metal matrix composites (MMCs) have a potential for enhanced wear conflict in
excess of the unreinforced aluminum alloy and are the most capable in achieving
enhanced mechanical properties. In the present investigation, composites of Aluminum
6061(Al6061) matrix material is reinforced with micron size Silicon carbide (μSiC)
reinforcement with 5, 10 and 15 weight percentages (wt.%) and nano size SiC (nSiC)
with 0.5, 1.0 and 1.5 wt.% are fabricated by stir casting technique. The stir casted
composites are further heat treated and the specimens are prepared as per ASTM
standards to conduct hardness and wear tests. The fabricated and heat treated nano
composites showed enhancement in hardness and wear resistance more than the micro
composites. The microstructure of the worn out specimen are examined by scanning
electron microscope. Taking into contemplation all the factors, it can be concluded that
aluminum based composite with 1.0% by weight nano SiC reinforcement acquire
superior wear resistance properties as compared to micro SiC reinforced aluminum
metal matrix composites.
EFFECT OF SILICON OXIDE (SIO2) REINFORCED PARTICLES ON AGEING BEHAVIOR OF Al-...IAEME Publication
Al-2024 alloy can be reinforced with different percentages of Silicon oxide particles using a stir casting method. The solution treatment of the composite sample and the unreinforced alloy was carried out at 550 ᴼC for 2h followed by aging at 150 ᴼC for various aging times between 1h and 5 hrs. The existence of SiO2 particles led to increasing the peak hardness of the alloy. The results revealed that peak hardness of the composite sample took place at shorter times than that of the unreinforced alloy for the samples solution treated for 2 h for both the composite and the unreinforced alloy that led to the fastest aging kinetics and the maximum hardness.
1-1 Influence of Multi Extrusion Die Process on Mechanical and Chemical Behav...Ahmed Ibrahim Razooqi
INFLUENCE OF MULTI EXTRUSION DIE PROCESS ON MECHANICAL
AND CHEMICAL BEHAVIOR OF 2024-T3 ALLOY.
Ahmed Ibrahim RAZOOQI
Technical Engineering College - Baghdad, Middle Technical University, Baghdad, IRAQ
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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.
e-mail [email protected]Effect of Heat Treatment on Some M.docxkanepbyrne80830
*e-mail: [email protected]
Effect of Heat Treatment on Some Mechanical Properties of 7075 Aluminium Alloy
Adeyemi Dayo Isadarea, Bolaji Aremob, Mosobalaje Oyebamiji Adeoyec,
Oluyemi John Olawalec*, Moshood Dehinde Shittuc
aPrototype Engineering Development Institute Ilesa, Nigeria
bCentre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria
cDepartment of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria
Received: April 14, 2012; Revised: September 3, 2012
This paper reports the effects of annealing and age hardening heat treatments on the microstructural
morphology and mechanical properties of 7075 Al alloy. The material was cast in the form of round
cylindrical rods inside green sand mould from where some samples were rapidly cooled by early
knockout and others gradually cooled to room temperature. From the samples that were gradually
cooled some were annealed while others were age hardened. Both the as-cast in each category and
heat treated samples were subjected to some mechanical tests and the morphology of the resulting
microstructures were characterised by optical microscopy. From the results obtained there is formation
of microsegregations of MgZn
2
during gradual solidification which was not present during rapid
cooling. It was also found out that age hardening and annealing heat treatment operation eliminated
these microsegregations and improve mechanical properties of 7075 Al alloy. It is concluded that
microsegregation can be eliminated by rapid solidification and appropriate heat treatment process.
Keywords: 7075 aluminium, microsegregation, precipitation hardening, annealing, magnesium alloy,
strength
1. Introduction
Aluminium and its alloys are used in a variety of cast and
wrought forms and conditions of heat treatment. For over
70 years, it ranks next to iron and steel in the metal market.
The demand for aluminium grows rapidly because of its
unique combination of properties which makes it becomes
one of the most versatile of engineering and construction
material1-3.
The optimum properties of aluminium are achieved by
alloying additions and heat treatments. This promotes the
formation of small hard precipitates which interfere with
the motion of dislocations and improve its mechanical
properties4-7. One of the most commonly used aluminium
alloy for structural applications is 7075 Al alloy due to its
attractive comprehensive properties such as low density, high
strength, ductility, toughness and resistance to fatigue8-11. It
has been extensively utilized in aircraft structural parts and
other highly stressed structural applications12-16.
But aluminium-zinc alloy as it is in 7075 Al alloy is
susceptible to embrittlement because of microsegregation
of MgZn
2
precipitates which may lead to catastrophic
failure of components produced from it17,18. The alloy is also
susceptibility to stress corrosion cracking19,20. This is .
Development of Aluminium Metal Matrix Composite Using Stir Casting Methodtheijes
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.
Experimental Analysis of Mechanical Properties on AA 6060 and 6061 Aluminum A...IJERA Editor
Due to the substantial increased in demands of aluminum in industries like automotive industry and building industry, it is required for improvement of its mechanical properties by addition of suitable alloying elements to aluminum. The objective of this research is to study the effect of various alloys addition to aluminum and their effects on tensile strength, hardness and microstructure. The mechanical properties of AA 6060 and AA 6061 aluminum alloy have been characterized in terms of tensile strength and hardness. The result has been used to determine the tensile strength and % elongation of the specimen. From the results, it has been observed that mechanical properties of Al-alloys increasing up to 0.65% of Mg addition due to grain refinement, where as increase in Mg contents beyond 0.71% mechanical properties starts decreasing. The microstructure of the fracture surface after tensile strength has been examined using inverted microscope.
Synthesis, characterization and mechanical behavior of nickel coated graphite...eSAT Journals
Abstract In this paper we are going to describe the characterization and mechanical behavior of the Nickel Coated Graphite (NCG) particle reinforced Al6061 metal matrix composite. Many a times, the composites fail to answer the question or fail to serve the purpose for which it is fabricated to. This is due to the less wetting nature between the reinforcement and the matrix and the impossibility of higher percentage of reinforcement addition in to the matrix. However, metal coated reinforcements have been able to overcome these limitations to a very extent. NCG particles reinforced Al6061 matrix with various weight percentages were fabricated by Squeeze casting method. Samples of 0, 5 and 10 wt% reinforcement addition were synthesized and characterized. Finally some useful conclusions were made. Keywords: Metal Coated Reinforcement; Nickel Coated Graphite; Squeeze Casting; Wetting.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
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Study of the Tribological behavior of as cast Al-4.2%Cu-Al2O3 composite
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 10, Issue 4 (Nov. - Dec. 2013), PP 50-59
www.iosrjournals.org
www.iosrjournals.org 50 | Page
Study of the Tribological behavior of as cast Al-4.2%Cu-Al2O3
composite
1
S. Srivastava, 2
P. K. Singh, 2
S. K. Singh, 1
Somya Yadav, 1
Yogesh Srivastav
1
Materials Science & Metallurgical Engineering
1
Maulana Azad National Institute of Technology, Bhopal, M.P. (India)
2
University of Technology, Barkatullah University, Bhopal, M.P. (India)
Abstract: The research work is carried out on the study of tribological property of aluminium based metal
matrix composite material, which is fabricated by using sol-gel technique. The composite material is prepared
through liquid metallurgy method by using varying percentage of Alumina and aluminium and fixed percentage
of copper 4.2%. Test sample billet is fabricated through casting method and has been examined the different
mechanical behaviour such as Vickers Hardness Number, Ultimate Tensile Strength, 0.2% Proof Stress, etc.
From the study, it has been observed that with increase in the alumina content in matrix the ductility of
composite show a contrary effect. The Pin-On-Disc test is used to evaluate the tribological property wear for
composite material and it is observered that tendency of wear rate has improved. The weight losses of the
specimen are measured and wear and friction characteristics are calculated with respect to time. Depth of wear
track, sliding speed, bearing load friction coefficient and wear volume have been shown large sensitivity to the
applied normal load and the testing time (or sliding distance). The XRD and SEM analysis are used to analyse
the wear debris and track; and silent conclusion has been drawn.
Key words: Tribological, composite, wear, pin-on-disc, friction, XRD, SEM.
I. Introduction
Aluminum matrix composites (AMCs) refer to the class of light weight high performance aluminum
centric material systems. The properties of AMCs can be tailored to the demands of different industrial
applications by suitable combinations of matrix, reinforcement and processing route. Presently several grades of
AMCs are manufactured by different routes. Three decades of intensive research have provided a wealth of new
scientific knowledge on the intrinsic and extrinsic effects of ceramic reinforcement vis-a-vis physical,
mechanical, thermo-mechanical and tribological properties of AMCs. In the last few years, AMCs have been
utilized in high-tech structural and functional applications including aerospace, defence, automotive, and
thermal management areas, as well as in sports and recreation. It is interesting to note that research on particle-
reinforced cast AMCs took root in India during the 70’s, attained industrial maturity in the developed world and
is currently in the process of joining the mainstream of materials. This work represents an overview of AMC
material systems on aspects relating to processing, microstructure, properties and applications.
II. Experimental investigation
Selection of materials
The material used in this work was commercially available 99⋅5% pure aluminum with a composition
given in table 1. Commercially pure aluminium is the product of the electrolytic cell process. In this experiment,
the composite of Al-Cu was prepared from commercial pure aluminum with the appropriate addition of 99.99%
small chips of pure tin-metal. Table 2 shows the physical and mechanical properties of pure aluminum.
TABLE 1: Chemical composition of the 99⋅5% pure aluminum.
Element wt.% Si Fe Ti V Cu Mn Al Others
0.063 0⋅36 0⋅003 0⋅006 0⋅002 0⋅037 99⋅557 0⋅002
2. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
www.iosrjournals.org 51 | Page
TABLE 2: Physical and mechanical properties of commercially pure aluminum
III. Procedure for preparation
The experimental set-up used for mixing and casting of composites is shown in Fig 16. It comprises of
a cylindrical sillimanite crucible of 150 mm diameter and 250mm depth with attachment of four baffles to its
sidewalls for proper dispersion of second phase in melt during stirring. The crucible was placed in an electric
heated muffle furnace. It was also equipped with a bottom pouring attachment, which could be closed or opened
by alumina stopper with a lever system. A steel mould was placed beneath the furnace to cast the molten metal.
In the top cover suitable opening was provided to charge materials and insert thermocouples. The temperature of
the furnace could be controlled with an accuracy of about ±50
C. Metallic bath temperature was measured
continuously by chromel /alumel thermocouple. The agitator system could be raised or lowered with the help of
the hanger and steel frame structure. After adjusting the mixer in a central position and required height from the
bottom of the crucible, the motor was bolted and locked while mixing of melt. Three-blade impeller was used
for effective mixing. This design provides very high rates of shear and only axial and radial flow currents are
utilized for mixing without any significant vortex formation due to the presence of baffles. The Al-Cu-Alumina
composites were prepared by liquid metallurgy methods. The required amounts of commercial (approximately
880-900g) pure aluminum with 65 g of copper were charged into the crucible and aluminum was heated to a
temperature 2000
C above its melting point i.e. 6620
C. A mechanical stirrer was inserted into the melt, and
agitation was started at a speed of 35 s-1
. Mixing was done for a period of 60 seconds. The emulsion was poured
into the chilled cylindrical mould placed beneath the crucible. The same procedure was adopted for different
compositions. Cylindrical casting of length 20cm and dia.2cm were obtained.
IV. Evaluation of as-cast Properties of the Composite
The wet chemical analysis was used to determine the percentage of iron in the bulk .The
metallographic specimens were prepared using standard technique and studied under SEM for different feature
present. The density of the composite was determined using Archimedes’ principle by weighing in water and
air. The hardness of the entire composite was measured using a Vickers hardness testing machine. The hardness
of the entire composite was measured using a Vickers hardness testing machine. The hardness was measured using
Vickers hardness instrument Leitz Welzlar at a load of 5Kg. At least 3 indentations have been taken for each point.
Tensile testing of all the Al-alloy-Alumina composite was performed stress along with percentage elongation and
reductions in area were computed from the results.
V. Wear test
Pin-on-disc machine was used for evaluating the wear properties under dry sliding condition. The
cylindrical test pin of 8mm diameter and 40mm length were used against a hardened steel disc of 120 mm
diameter. Wear tests were conducted with variable applied pressure 3.9x10-1
MPa and a sliding speed of 0.5 m/s
with a constant sliding distance of 10000 meters. Wear test were also conducted with selected varying speeds
and sliding distance ranging up to 1000 meters. The initial weight of the specimen was determined in a digital
balance with a precision of ± 0.1 mg. The pin was kept pressed against a rotating steel disc of hardness 58 HRC
under loaded condition. The frictional traction en-counted by the pin in sliding is measured by a PC based data
logging system. On completion of the running through the required sliding distance the specimen pins were
cleaned with acetone, dried and their weight were again determined for ascertaining the weight loss. Wear
debris were analyzed by XRD.
VI. Result and Discussion
1. Physical investigation
The liquid metallurgy methods were used to synthesize the composite materials with different amount
of the alumina content in the matrix. The theoretical density of the composite materials varies from 2.88 g/cc to
2.84 g/cc with alumina content. But the experimental density of the composite materials was found to vary from
2.72 g/cc to 2.70 g/cc along with porosity varies from 5.2 % to 4.9 %. The XRD methods were used to
Typical mechanical properties
Density 2.7g/m3
0.2% yield strength 20MPa
UTS 70MPa
Elongation 50%
Hardness 170Hv
3. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
www.iosrjournals.org 52 | Page
investigate the different phase/element present in the prepared composite materials. Fig 18 shows the XRD
pattern of prepared nano Al2O3 with (012), (104), (110), (133), (024), (116), (018), (214), (119) at an angle of
25.594°, 35.197°, 37.804°, 43.381°, 52.588°, 57.538°, 61.333°, 66.547°, 68.230°. Fig 12(b) shows the XRD
pattern of Al2O3. The XRD scanning from 10°- 80° shows the lines for alumina, 38.86°, for aluminum
respectively.
2. SEM investigation
In casting a homogeneous single phase liquid is cooled below the liquidus line, it transforms into two
liquids, namely aluminum rich and copper rich. The minor ‘Cu’ rich phase segregates out. If the homogeneous
single Al-Cu liquid phase is rapidly cooled, then the minor phase is dispersed uniformly in aluminum rich
matrix. The microstructure of the alloys was investigated by using SEM. Fig. 17 shows the microstructure of
commercially pure aluminum along with composite in Fig. 18. Here copper and Al2O3 nanoparticles is
distributed in aluminum matrix as a separate phase in form of reticular (network) structure along the edges of
aluminum grains with the proper uniform distribution.
3. STUDY OF THE MECHANICAL PROPERTIES
TABLE 3: Mechanical properties of the Al-4.2%Cu-3.4%Alumina composite
The resistance to indentation or scratch is termed as hardness. Among various instruments for measurement of
hardness, Brinell’s, Rockwell’s and Vickers’s hardness testers are significant. Theoretically, the rule of mixture
of the type Hc=vr Hr+vm Hm (suffixes ‘c’, ‘r’, and ‘m’ stand for composite, reinforcement and matrix respectively
and v and H stand for volume fraction and hardness respectively) is valid for composite materials which helps in
approximating the hardness values. Among the variants of reinforcements, the low aspect ratio particle
reinforcements are of much significant in imparting the hardness of the material in which they are dispersed.
Table 6 shows a comparison of the mechanical properties of Al-Cu/Al2O3 composite samples produced by the
liquid metallurgy methods. Fig. 16 shows the variation of mechanical properties with the Alumina content in the
Al-Cu alloys. It is observed that the hardness of the composite materials increases with increasing the alumina
content in the matrix. Alumina is a very ductile materials and it is responsible a factor for increasing the
hardness of the materials.
1 2 3 4 5 6 7 8 9
80
100
120
140
160
180
Mechanicalproperties
Alumina Content (wt%)
VHN
UTS
PS
Fig.1: Variation of hardness with varying alumina content
The uniform distribution and the nature of the interfacial bonding between alumina particles and matrix have an
important relationship on the mechanical properties of a composite material. It has been suggested that alumina
particles, being very hard compared to the aluminium matrix, may be treated as load-bearing constituents. With
a view to extending their applications to structural components, these materials should have a good combination
of strength and ductility. The Al-Cu/Alumina composites with different Al2O3 content show an decrease in the
tensile elongation together with an increase in the ultimate tensile strength of the material, resulting from the
better dispersion of the particles. The magnitudes of these decreases are observed to average approximately
S.No. Composite VHN UTS(MPa) 0.2%PS(MPa) % elongation
1 Al-4.2%Cu-1.6%Al2O3 96.2 147.3 72.9 19.3
2 Al-4.2%Cu -2.7%Al2O3 99.6 152.3 79.1 18.1
3 Al-4.2%Cu -3.4%Al2O3 104 158.4 83.2 17.3
4 Al-4.2%Cu -5.6% Al2O3 109 165.3 87.4 16.9
5 AL-4.2%CU -8.4% AL2O3 116 173.2 93.2 16.3
4. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
www.iosrjournals.org 53 | Page
18%. A strong bond between the reinforcement and matrix helps in the load transfer from the latter to the
former. As a result, fracture takes place in the composite via the reinforcement and not along the interface [1, 2].
Although the alumina is a load bearing constituent, a strong particle/matrix interface helps alumina particles
embed themselves into the matrix properly, improving the wear resistance.
VII. Wear study
1. Effect of sliding distance and load
The variation of bulk wear with sliding distance was studied at different combinations of loads and
sliding velocities. Almost a linear relationship in bulk wear and sliding distance i.e. steady state wear is
observed after an initial running-in period of 500–1000 m in almost all the cases irrespective of load or sliding
velocity used. Fig 2 shows the results for a test conducted at 2 kg load and 0.5m/s sliding velocity. In running
period, the Al-Cu/Alumina composite shows large wear rates. The relation found here is in accordance with the
pattern for most metallic materials derived theoretically as well as observed experimentally [3, 4]. But
irrespective of variables used, bulk wear is large with large alumina content in Al-Cu/Alumina composite. The
free alumina particles are released from the composite material during dry sliding of mating surfaces form a
lubricant film at the interface. Shows the variation of rise in temperature of the test specimen during experiment
with sliding distance. The maximum rise in temperature is found in Al-4.2%Cu-8.4%Al2O3 and minimum in
Al-4.2%Cu-1.6%Al2O3. This type of the behaviour can be explained on the basis of thermal conductivity. Al-
4.2%Cu-1.6%Al2O3 shows high conductivity as Al-4.2%Cu-8.4% Al2O3. Fig.5 shows the SEM micrographs of
wear tracks of Al-Cu/Al2O3 composites (Al-4.2%Cu-3.4%Al2O3) for 2 kg applied load and 0.5 m/s sliding
velocity at 10,000 m sliding distances. This micrograph was taken at the higher magnification (X6000). This
figure is clearly revealed the presence of the oxide layer which might be adhered on the rubbing surface.
2. Effect of applied load
The studies conducted to see the effect of applied load on wear rate revealed that wear rate increases
continuously with load in a linear manner irrespective of the sliding velocity used as it is evident from Fig.6 for
a particular velocity. But in all the cases wear rate first increases with increase in alumina content for all
combinations of loads and sliding velocities used in the present investigation and then increases with decrease
the alumina content. Corresponding temperature curve shown in, clearly reveal that temperature continuously
increases with increase in load but with increase in copper percentage in composite an increase in temperature
rise is observed which is indicative of larger heat dissipation capability of copper. the variation of temperature
and micro hardness of the test specimen with the variation of load. With increase the load on the test specimen,
the composite material bears maximum rise in temperature. The materials at the contacting surface on the pin-
on-disc become soften, which is responsible factor for decreasing the micro hardness of the contacting surface.
0 2000 4000 6000 8000 10000
2
4
6
8
10
12
14
Commulativewear,m
3
x10
-9
Sliding Distance (km)
1.6 % Al2
O3
2.7 % Al2
O3
3.4 % Al2
O3
5.6 % Al2
O3
8.4 % Al2
O3
Fig.2: Variation of bulk wear with sliding distance at 2 kg load and 0.5 m/s sliding velocity for
as-cast Al-Cu/Al2O3 composites.
Fig.3: SEM micrographs of wear tracks of Al-Cu/Alumina composites (Al-4.2%Cu -
3.4%Alumina) for 2 kg applied load and 0.5 m/s sliding velocity at 10,000m sliding distances.
5. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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Fig.5 shows the SEM micrographs of wear tracks of Al-Cu/Al2O3 composites (Al-4.2%Cu-3.4%Al2O3) at the
higher magnification for 2 kg applied load and 0.5 m/s sliding velocity at 3000 m sliding distances. The oxides
layer with small amount of the alumina particles are adhered on the material surface. Fig 6 (a) and Fig 6 (b)
shows the SEM micrographs of wear tracks of Al-Cu/alumina composites (Al-4.2%Cu-3.4% Al2O3) for 15 kg
applied load and 0.5 m/s sliding velocity at 3000 m sliding distances (a) worn surface (b) crack surface. The
degree of surface damage (i.e. depth and width of the grooves) depended on the applied load and microstructure
of the material. At the higher load, generally metallic failure is observed as shown in Fig 28 (a). For observing
the mechanistic phenomena at the higher load, the SEM micrograph was taken at the higher magnification, as
shown in Fig 6 (b). While studying the wear tracks at different loads for a particular velocity (from 2 to 15 Kg)
the operating modes changes from oxidative-to oxidative and metallic to metallic as load applied is increased
and wear track observes broken oxide film, deep grooves and delaminating of surface as evident from Fig 6 (b).
In this SEM micrograph some small crack was found at the oxide surface. With increase the load, the produce
cracks within the material by sliding action easily propagate and the form oxidative film at lower load are
ruptured as shown in Fig 6 (b) at 15 Kg load and 0.7m/sec sliding velocity
4 6 8 10 12 14 16
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
WearRate(m
3
/m
3
x10
-12
)
Load (kg)
1.6 % Al2
O3
2.7 % Al2
O3
3.4 % Al2
O3
5.6 % Al2
O3
)
8.4 % Al2
O3
Fig.4: Variation of wear rate with load at 0.5 m/s sliding velocity and running distance 3000 m
for as-cast Al-Cu/ Al2O3 composites
Fig.5: SEM micrographs of wear tracks of Al-Cu/Alumina composites (Al-4.2%Cu-3.4% Al2O3)
for 2 kg applied load and 0.5 m/s sliding velocity at 3000 m sliding distances.
Fig.6: SEM micrographs of wear tracks of Al-Cu/ Al2O3composites (Al-4.2%Cu-3.4% Al2O3) for 15 kg
applied load and 0.5 m/s sliding velocity at 3000 m sliding distances (a) worn surface (b) crack surface (c)
Al2O3
3. Study of the sliding velocity
The role of alumina in sliding contact is provided by layered-lattice structure. The bonds between the
parallel layers are relatively strong. The adsorbed water vapor and other gases from environment onto the
crystalline edges weaken the interlayer bonding forces. It results in easy shear and transfer of the crystalline
platelets on the mating surfaces. Fig 7 shows the variation of wear rate with sliding velocity at 2 kg load, 3000m
6. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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running distance. Like all other aluminium alloys/ composites, Al-Cu/ Al2O3 composites also show an initial
decrease in wear rate followed by a sharp increase in wear rate after attaining minima with increase of sliding
velocity for all composites at different loads. But in all the cases wear rate decreases with increase in alumina
content for (say up to 3.4 % Al2O3 in the matrix) all combinations of loads and sliding velocities used. While
that wear rate again decrease with increase the alumina content in the matrix.
Further, variation of wear rate and hardness of worn wear track surface is shown in Fig 8. It clearly
shows highest hardness at minima in wear rate, which is clearly indicative of the presence of hard oxide
particles. With increase in sliding velocity, an oxides particle is removed from the mating surface, due to
decrease the hardness of the composite materials and hence increases the wear rate. For temperature increase
with sliding velocity follows the same trend as observed in the case of variation of temperature with applied
load. Higher velocity gives higher amount of wear loss due to fast rubbing of the contacting surface. Therefore
maximum rise in temperature in the test specimen at the contacting surface occurs. The SEM observations of the
wear tracks at 2.0 Kg load for different sliding velocities are shown in Fig.9 (a–b) and 10(a–c). In Fig.9 (a-b)
shows the SEM observation at the lower and the higher velocity and Fig 10(a-c) show SEM result at the
optimized velocity. SEM micrograph of the wear track in Fig 9(a) was mainly comprised of oxide particles and
the wear track surface is seen to have more pronounced layer of oxide particles adhered at the surface of the
materials. But at the higher velocity, metallic particles come out during wear processes and wear track is seen
clear and smooth as shown in Fig.9 (b).
The minima in the wear rate was found at 1.22 m/sec. Fig. 16 show SEM micrographs of wear tracks of
Al-Cu/ Al2O3 composites (Al-4.2%Cu-3.4% Al2O3) for 2 kg applied load and 1.22 m/s sliding velocity at 3000
m sliding distances (a) worn surface (b) crack observation (c) observation of the oxide layer. Wear rate
continuously increases with increase the sliding velocity due to the formation of thin film of oxide layers along
with metallic layer at the mating surface as shown in Fig 10 (a). This is confirmed from the SEM observation of
the wear track taken at the higher magnification as shown in Fig.10(b).
The oxide layer of the respective metals adhered on the mating surface is clearly visible in this
micrograph. The failure of the materials from the wear process is due to formation and propagation of the crack
within the materials as shown in Fig 10(c). The cracks are formed at the adjacent surface of the materials. An
examination of the three micrographs shows the formation of severe patches and grooves resulting from plastic
deformation of the aluminium alumina composite and relatively small groves and mild patches on 3.4 wt %
alumina composite. This reduction in severity of the worn surface of the composite material is due to the
formation of a Al2O3 lubricating film which prevents the direct contact of the specimen with the rotating steel
disc surface. This formation of the lubricating layer at the sliding surface becomes thicker with more alumina as
the addition of Al2O3 content to the base alloy increases and it is responsible for playing an effective role for
keeping the wear behaviour of the composite low.
4. Study of the surface particles and its mechanistic approach
Figure 11 (a-b) shows the SEM micrograph of wear debris for 2 kg applied load and 1.22 m/s sliding
velocity at 3000 m sliding distances (a) collecting particles (b) examination of the alumina particles. This
observation has been also confirmed by XRD observation as shown in Fig.12. Debris in all figures was mainly
comprised of oxide particles of aluminum and tin. But it also contained some small amount of alumina as shown
in Figure 11(b). In the XRD observation, the aluminum oxide, tin and its oxides (from EDAX observation) and
alumina are found as the main peak. Tin and lead are weak and ductile and hence they decrease the strength
property of aluminium alloys under study. Further, Cu/ Al2O3, being a ductile material, deforms in preference to
the stronger matrix. This reduces the stress concentration in the matrix and makes it more deformable. It is also
found that the alloys containing tin have slightly more strength and hardness but low ductility values compared
to the alloys containing lead.
Al wear particles on the worn surfaces are laminated by the pin on the contact area, forming plough.
Because wear particles contain some aluminum oxide, Zhou et al believed that the oxidation wear was the main
wear mechanism of composites [5]. However, according to the SEM observation of worn surfaces of the
composite and the study of delamination theory of wear, it can be concluded that the delamination wear could be
the main wear mechanism. Dislocations at the mating surface, subsurface crack and void are induced due to the
repeated plastic deformation between the test pin and disc. The cracks extend later and cause break and split of
the hardened surface layer by shear deformation mechanism [6-10].
7. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
WearRate(m
3
/m
3
x10
-12
)
Velocity (m/sec)
1.6 % Al2
O3
2.4 % Al2
O3
3.4 % Al2
O3
5.6 % Al2
O3
8.4 % Al2
O3
Fig.7: Variation of wear rate with sliding velocity at 2 kg load for Al-Cu/ Al2O3 composites.
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Velocity(m/sec)
Wearrate(m
3
/m
3
)x10
-12
90
100
110
120
130
140
150
160
Microhardness
Fig.8: Variation of micro-hardness and wear rate of worn surface with sliding velocity at 2 kg
load.
Fig.9: SEM micrographs of wear tracks of Al-Cu/ Al2O3 composites (Al-4.2%Cu-3.4% Al2O3)
for 2 kg applied load and 0.5 m/s sliding velocity at 3000 m sliding distances (a) worn surface at
0.25m/sec (b) worn surface at 3.53m/sec
Fig.10: SEM micrographs of wear tracks of Al-Cu/ Al2O3 composites (Al-4.2%Cu-3.4% Al2O3)
for 2 kg applied load and 1.22 m/s sliding velocity at 3000 m sliding distances (a) and (b) worn
surface (c) observation of the oxide layer
8. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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Fig.11: SEM micrographs of wear debris of Al-Cu/ Al2O3 composites (Al-4.2%Cu-3.4% Al2O3)
for 2 kg applied load and 1.22 m/s sliding velocity at 3000 m sliding distances (a) collecting
particles (b) examination of the alumina particles.
10 20 30 40 50 60 70 80
0
200
400
600
800
1000
1200
Intensity
2 x Theta
Fig.12: (a) XRD of the wear debris. b) XRD of Al2O3.
5. Friction studies
The characterization of friction behaviour of Al-Cu/Alumina base composite with sliding at the specific
load (i.e. 10N) is illustrated in Fig 13. The Figure show is graphically representation of the results obtained from
the friction experiment at a fixed load and sliding velocity. It is evident from the Fig.13 the friction coefficient
drastically increases during the running in period. During the steady state period the friction coefficient is being
stabilized. In dry sliding, the reason for increasing the wear rate and the coefficient of friction of Al-Cu/ Al2O3
composite as compared with the base alloy is the presence of alumina layer at the sliding surface which acts as
the best solid lubricant. The friction behaviour also varies with applied load. The average value of the friction
coefficient at normal load is shown in Fig.14. In accordance with the figure the decrease of the friction
coefficient corresponds to increase the normal load. The increase rate is especially evident for load change from
10 to 50 kg. On increasing the applied load, lubricating condition of the alumina improves; the alloy
composition starts to play its role in determining the running ability of the test under friction. Fig.15 shows the
variation of coefficient of friction with wt % of alumina content in the matrix. The friction coefficient of the test
materials increases with increase the alumina content in the matrix. With increasing the alumina content, the
thickness of the lubricating film and the amount the alumina in the lubricating film decreases. The alumina
comes more and more contact with sliding surface and results in lowering the frictional coefficients of the
composite materials. The worn surfaces of the samples from the SEM examination are shown in Fig 16. The
worn surfaces of the (Al-4.2%Cu-3.4% Al2O3) samples were noticed to be smoother than those of the (Al-
4.2%Cu-3.4% Al2O3). Generally, the parallel ploughing grooves and scratches can be seen over all the surfaces
in the direction of sliding. These grooves and scratches resulted from the ploughing action of asperities on the
counter disc of significantly higher hardness. The worn surfaces of the samples from the SEM examination are
shown in Fig.16 (a & b). The worn surfaces of the test sample were noticed to be smoother at the higher load
than at the lower load as shown in Fig 14. Generally, the parallel ploughing grooves and scratches can be seen
over all the surfaces in the direction of sliding. These grooves and scratches resulted from the ploughing action
of asperities on the counter disc of significantly higher hardness [11-13].
9. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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0 1000 2000 3000 4000 5000
0.28
0.29
0.30
0.31
0.32
0.33
0.34
0.35
0.36
0.37
0.38
0.39
0.40
0.41
0.42
FrictionCoefficient
Sliding Time (Sec)
1.6 % Al2
O3
2.7 % Al2
O3
3.4 % Al2
O3
5.6 % Al2
O3
8.4 % Al2
O3
Fig.13: Friction coefficient variation of Al-Cu/ Alumina composite during sliding time at fixed
specific loads (i.e. 10N) and sliding speeds (1.22 m/sec)
20 25 30 35 40 45 50
0.40
0.41
0.42
0.43
0.44
0.45
0.46
0.47
0.48
0.49
0.50
0.51
0.52
0.53
0.54
FrictionCoefficient
Load (kg)
1.6 % Al2
O3
2.7 % Al2
O3
3.4 % Al2
O3
5.6 % Al2
O3
8.4 % Al2
O3
Fig.14: Coefficient of friction vs. applied load for Al-Cu/ Al2O3 composite at 0.932m/sec
2 4 6 8 10
0.38
0.40
0.42
0.44
0.46
0.48
FrictionCoefficient
Alumina content (wt %)
Fig.15: Variations in the coefficient of friction with the wt % of Al2O3 in the matrix.
Fig.16: SEM micrographs of wear debris of (Al-4.2%Cu-3.4% Al2O3) for 2 kg applied load and
1.22 m/s sliding velocity at 3000 m sliding distances (a) at lower loads (b) at higher loads
10. Study of the Tribological behavior of as cast-Al-Sn/Graphite composite
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VIII. Conclusion
1. The Al-Cu/Alumina composite is being prepared from liquid metallurgical methods. It can be observed from the
present investigation that alumina could be successfully and uniformly distributed in aluminium-Copper base
matrix using impeller mixing chill casting technique.
2. UTS (Ultimate Tensile Strength), 0.2% PS (Proof Stress) and VHN (Vickers Hardness Number) increased with
increases the volume fraction of the alumina in the matrix.
3. The Al-4.2% Cu-8.4% Al2O3 composite showed lower percentage of elongation while compared to Al-4.2%Cu
-1.6% Al2O3 From the present investigation we have also observed that the ductility of composite decreases with
increase the percentage of alumina.
4. The hardness is another affecting parameter which affects the rate of wear, increases with decreases the
percentage of alumina in the matrix.
5. Wear rate with sliding distance shows almost a linear relationship for all combinations of loads and sliding
velocities and composites.
6. Wear rate increases continuously with applied load for all the sliding velocities and composites studied.
7. Low loads and sliding velocities are dominated by oxidative debris whereas higher loads and sliding velocities
are dominated by metallic debris.
8. At low loads and sliding velocities wear track surface is largely covered with oxide layer and smooth in nature
but at higher loads or sliding velocities surface is highly deformed with deep grooves and gross delaminating
occurs leading to larger wear rate.
The coefficient of friction decreases with increase the alumina content in the matrix.
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