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Aluminium matrix composites (AMCs) have found uses in aircraft, rocket engineering, vehicle engineering, energy sector, infrastructure areas, marine and military applications, sports and recreation utilization because of its enormous mechanical strengths and sensible wear resistance features. The experimental results of 7075Al-WC-Co composites’ mechanical and tribological properties are provided in this article. The matrix is Al7075 and the reinforcement is planetary ball milled WC-Co in cermet form with particulates size range from 30-40 μm. Liquid metallurgy route was followed to develop 7075Al composites reinforced with 6, 9 and 12 wt.% of WC-Co. The tests were carried out on 7075Al and composites in accordance with ASTM specifications. According to the experimental results, the hardness of 7075Al-WC-Co composites is discovered to be raised by increasing the percentage volume of cermet phase. Wear attributes of the WC-Co containing composite were superior in terms of wear resistance. The manufactured composites were characterized using SEM and EDAX. Worn surface of the composite samples are studied before and after wear test.

In the current studies an investigations were made to know the effect of 63 micron sized B4C particles addition on the mechanical and wear behavior of aerospace alloy Al2618 metal composites. Al2618 alloy with different weight percentages (2, 4, 6 and 8 wt. %) of 63 micron sized B4C particles reinforced composites were produced by stir cast process. These synthesized composites were tested for various mechanical properties like hardness, compression strength and tensile behavior along with density measurements. Further, microstructural characterization was carried by SEM/EDS and XRD analysis to know the micron sized particles distribution and phases. Wear behavior of Al2618 alloy with 2 to 8 wt. % of B4C composites were studied as per ASTM G99 standards with varying loads and sliding speeds. By adding 63 micron sized B4C particles hardness, compression and tensile strength of Al2618 alloy was enriched with slight decrease in elongation. Further, wear resistance of Al2618 alloy was enriched with the accumulation of B4C particles. As load and speed on the specimen increased, there was increase in wear of Al2618 alloy and its composites. Various tensile fracture surface morphology and worn surface behavior was observed by SEM analysis.

In the current investigation, efforts are being made to produce an Al2014-Al2O3p composite with variable particle size of 88 mm by liquid stir casting route. 9, 12 and 15 weight proportions of Al2O3p were added to the Al2014 base alloy. By using SEM and EDS testing, microstructural studies have been conducted. Al2014-9, 12 and 15 weight proportion of Al2O3p composites mechanical behavior is determined in line with ASTM standards. Electron microscopic images showed that alumina (Al2O3p) particles are dispersed uniformly within the Al2014 composite matrix. EDS study confirmed the proximity of Al and O elements to composites reinforced by Al2O3p. It is also found that Al2014-Al2O3p composite hardness, UTS, and yield strength are improved by the addition of 9, 12 and 15 weight proportion of Al2O3p. Due to the addition of alumina particles in the Al2014 matrix alloy, the ductility of the produced composites decreases. Tensile fractography is performed using SEM to consider the mechanisms for failure.

In the present examination, the mechanical properties of Al2218-nano B4C composites displayed. The composites containing 4 to 8 wt. % of nano boron carbide in ventures of 4 wt.% were readied utilizing liquid metallurgy method through stir casting. For every composite, fortification particles were preheated to a temperature of 400˚C and afterward added in ventures of two into the vortex of liquid Al2218 compound to improve the wettability and dispersion. Microstructural examination was carried out by SEM and elemental investigation was finished by EDS. XRD Analysis used to recognize the B4C phases in the Al grid. Density, tensile, compression and hardness tests were done to distinguish various properties of composites. The aftereffects of this investigation uncovered that as the weight % level of nano B4C particles were expanded, there was noteworthy increment in hardness, UTS, yield and compression strength of Al2218 amalgam composites. Further, there was slight drop in the density and malleability of the Al2218 amalgam composites when contrasted with the base. Tensile fractured surfaces analysis was conducted by using SEM.

Al2O3 may be the most important reinforcement in aluminum-based composites that are rising quickly in modern years. The significance of this paper is to study the influence of Al2O3p size variation (i.e. 53 µm and 88 µm) and content (i.e. 9, 12, and 15Wt %) on density, hardness, tensile strength, elongation to fracture and wear studies. During the preparation of each composite, the ceramic reinforcements were introduced in a novel way which involves two-stage additions of reinforcements during liquid stirring. It has been found that because the size of the Al2O3p is reduced, measurement of the density showed that 2014Al-Al2O3p composites contained slight porosity and also the quantity of porosity among the prepared composites higher with diminishing the Al2O3p size and increasing weight percentage of Al2O3p. In addition to this, the results show that by decreasing the Al2O3p size and increasing the weight proportion of the Al2O3p the tensile strength and hardness of the prepared composites increase. Microstructural characterization carried out for the 2014Al-Al2O3 composites using scanning electron microscopy (SEM) which showed a fairly homogeneous distribution of Al2O3p with grain refinement of the matrix. Wear test is conducted for the prepared composites by utilizing a computerized pin on disc wear testing machine which shows greater wear resistance property as the size of the Al2O3p reduced.

The demand for materials with an unusual combination of properties has increased tremendously at a level that cannot be attained through the use of conventional materials. This is especially true for materials used in aircraft, automotive and power generation applications. The microstructure and mechanical properties of Al7075 – 6, 9 and 12 wt.% WC-Co particles reinforced composites are shown in this study. Liquid metallurgy is used to create the composites. The planetary ball milling method is utilized to turn the WC-Co mixtures into cermets, and the particles with a size range of 30-40 µm are employed as reinforcement. SEM and EDS analyses were used to characterise the microstructure. ASTM standards are used to test the mechanical characteristics of both as cast Al7075 and Al7075-6, 9 and 12 wt.% WC-Co composites. SEM was used to perform fractography study on the prepared composite.

In the present study looked into how incorporating B4C particles with a size range of 20–25 microns would affect the mechanical, wear and physical properties of composites made from Al7010 alloy. The stir cast method accounted for of the total production of B4C composites. Different mechanical properties, such as hardness, tensile behaviour, wear and density, were measured and analysed for these synthetic composites. Microstructure was characterised by scanning electron microscopy and X-ray diffraction analysis to determine the distribution and phases of particles smaller than a micron. Wear tests were conducted on all the samples at varying loads and speeds. Hardness and tensile strength of Al7010 alloy were improved by adding B4C particles sized 20–25 microns, with only a minor decrease in elongation. Further, as B4C particles accumulated, the density of the Al7010 alloy decreased. SEM examination revealed a wide range of fracture behaviours upon tensile stress. Load and sliding speeds affected the wear behaviour of Al7010 alloy and its composites.

In metallurgy, the microstructure study is very important to evaluate the properties and performances of a material. The Monte Carlo method is applied in so many fields of Engineering Science and it is a very effective method to examine the topology of the computer-simulated structures and exactly resembles the static behavior of the atoms. The effective 2D simulation was performed to understand the grain growth kinetics, under the influence of second phase particles (impurities) is a base to control the microstructure. The matrix size and [Formula: see text]-states are optimized. The grain growth exponent was investigated in a polycrystalline material using the [Formula: see text]-state Potts model under the Monte Carlo simulation. The effect of particles present within the belly of grains and pinning on the grain boundaries are observed. The mean grain size under second phase particles obeys the square root dependency.

In the present investigation, an endeavor has been made to create copper-zinc-nano ZrO2 particulates strengthened composites by utilizing liquid stir technique. 4, 8 and 12 wt. % of nano ZrO2 particulates were added to the Cu-10 wt. % Zn base grid. Microstructural studies were finished by utilizing SEM and EDS examinations. Wear behavior of Cu-Zn-4, 8, 12 wt. % of nano ZrO2 composites were assessed according to ASTM G99 benchmarks. Scanning electron micrographs uncovered the uniform dispersion of nano ZrO2 particulates in the copper zinc composite network. EDS examination affirmed the nearness of Zr and O components in nano ZrO2 strengthened composites. The experiments were conducted at a constant speed of 400rpm and sliding distance of 3000m over a varying load of 1, 2, 3 and 4 kg. Similarly, at a constant load of 4 kg and sliding distance of 3000m over a varying sliding speed of 100, 200, 300 and 400rpm. The results showed that the wear resistance of Cu-Zn-4, 8% and 12% ZrO2 nano composites were superior than the as cast alloy. As load and speed increased the height loss in the composites and alloy was increased. Worn surface morphology was studied by using SEM.

MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines, results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.

Because of the good shape memory effect and superelasticity, copper-based shape memory alloys (SMAs) with aluminum and beryllium as binary and ternary elements are widely used in many applications (Cu-Al-Be SMAs). However, they are prone to corrosion in atmospheric conditions. This alloy is susceptible to corrosion due to hydrogen. This affects the characterization of the SMAs by absorbing the hydrogen and results in hydrogen embrittlement, makes changes in SME and SE effect. The process of hydrogen absorption was carried out under electrolytic charging under constant current density and the charged specimens were aged in the air at room temperature. The results show the decrement in SME from 99.8 % to 62%, and the tensile test revealed an increment in the transformation stress level from 200MPa- 290MPa in the case of the charged specimen.

In the present research Al7075 alloy with 1, 3 and 5 varying weight percentages of flyash, 1, 2 and 3 varying wt.% of red mud along with constant 4 wt.% of mica particles composites were synthesized by stir casting technique. Thus prepared Al7075 alloy composites were subjected to the microstructural characterization using SEM and EDS. Mechanical properties were evaluated to know the impact of multi micro particles addition on the hardness, ultimate strength, yield strength, and ductility behavior of Al7075 alloy composites. Further, wear behavior of the prepared Al7075 alloy with mica, flyash and redmud composites were experimented using pin-on-disc apparatus by varying normal load and sliding velocity at constant 3000 m sliding distance. The improved mechanical properties were observed with the addition of micro scaled flyash, redmud and mica particles, further improvement was attained with the increasing weight percentage of flyash and red mud in the Al7075 matrix alloy. However, there was decrease in the ductility of the composites with an incorporation of hard micro particles in the soft Al matrix. Fractography and worn surface analysis were carried out to know the influence of micro particles on the tensile failure and wear surfaces of the composites.

In the present investigation, microstructure study and tensile behavior of B4C particulate reinforced Al2024 alloy composites have been reported. Al2024 matrix composites containing boron carbide were fabricated by conventional stir casting method. The composites containing 3 and 6 wt. % of B4C (80 micron size)particulates were fabricated for the study. The micro- structure of the composite was examined by optical microscopy. Images were taken to identify the presence of B4C particle in aluminum matrix. Further, tensile behavior of as cast Al2024 alloy and Al2024-3 wt. % B4C and 6 wt. % B4C composites were studied. Tensile properties like ultimate tensile strength, yield strength and percentage elongation were evaluated as per ASTM standards. Microstructural observation revealed the uniform distribution of particles in the Al2024 alloy matrix. It was found from the analysis, that the ultimate tensile strength of composite was increased due to increasing amount of boron carbide particle in the composite and the yield strength was increased due to the higher value of boron carbide. Also percentage elongation of the composites decreases with increase of the order of boron carbide. Finally, it was found that in the stress - strain curve, the boron carbide was the main factor in improving the tensile strength of composites because of its high hardness. The composites in the present study have great potential for application as structural materials.

In the present investigation synthesis, microstructure, mechanical and wear behavior of 5 weight percentage of nano Al2O3 particulate reinforced AA7475 alloy composites has been reported. AA7475 matrix composite containing nano Al2O3 were fabricated by conventional stir casting method. The microstructures of the composites were examined by scanning electron microscopy. Further, mechanical and wear behavior of as cast AA7475 alloy and AA7475 - 5 wt. % nano Al2O3 composites were studied. Mechanical properties like hardness, ultimate, yield strength and percentage elongation were evaluated as per ASTM standards. Pin on disc apparatus was used to conduct the dry sliding wear tests. The experiments were conducted by varying loads and constant sliding speed of 300rpm for sliding distance of 4000m. Microstructural observation revealed the uniform distribution of particles in the AA7475 alloy matrix. From the analysis, it was found that the hardness, ultimate tensile strength and yield strength of composites were increased due to addition of nano Al2O3 particle in the AA7475 alloy matrix. Percentage elongation of the composite decreased in 5 wt. % nano Al2O3 reinforced composites. Further, the volumetric wear loss was found to increase with the load and sliding distance for all materials. Worn surface analysis made by using scanning electron micrographs to know the various mechanisms involved in the wear process.

Nano particulates fortified metal lattice composites are finding extensive variety of utilizations in car and sports hardware fabricating businesses. In the present investigation, an endeavor has been made to create copper-zinc-nano ZrO2 particulates strengthened composites by utilizing fluid liquefy technique. 4, 8 and 12 wt. % of nano ZrO2 particulates were added to the Cu-Zn base grid. Microstructural studies were finished by utilizing SEM and EDS examination. Mechanical behavior of Cu-Zn-4, 8, 12 wt. % of nano ZrO2 composites were assessed according to ASTM benchmarks. Checking electron micrographs uncovered the uniform dispersion of nano ZrO2 particulates in the copper zinc composite network. EDS examination affirmed the nearness of Zr and O components in nano ZrO2 strengthened composites. Further, it was noticed that hardness, UTS, yield quality of Cu-Zn composite expanded with the expansion of 4, 8 and 12 wt. % of nano ZrO2 particulates. Ductility of nano composites was decreased by adding zirconium oxide particulates. Fractography of tensile specimens were carried out by using SEM micrographs to understand the failure mechanisms. &nbsp

In this research, work is carried out on Al6082 alloy because of its thermal stability and stiffness which can be used for strong structural application, here the hard ceramic particle of Si3N4 are reinforced with Al6082 for further enhancing its strength, stiffness. Stir casting technique is used to fabricate aluminum metal matrix composition with varying wt. % of Si3N4, this technique involves cost effective process and also results in homogenous mixture between the matrix and the reinforcement. The percentage of reinforcement varies from 0 and 9wt%. When subjected to severe plastic deformation it tends to change the grain size from micron to submicron level size in the grain structure by the application of load. The scanning electron microscope reveals the distribution of Si3N4 on the surface of the sample. The hardness value increased as compared to as-cast Al6082 alloy.

The present work dry sliding wear behaviour of Al7075 alloy matrix composite reinforced with 9Wt. % of WC-Co particulates is examined after prepared by stir casting. The dry sliding wear behaviour was studied for the composites with parameters of varying sliding speed, load and sliding distance. Microstructure characterization is done using SEM/EDX studies for the composite samples. From microstructural characterization even distribution of WC-Co particulates is observed in Al7075 matrix. DUCOM wear testing machine with EN32 steel disc is used to evaluate the wear rate of the composite. Worn out surface of the composite is subjected to SEM analysis to observe the layer formations. From the results of wear studies it is observed that the composite wear rate is reduced by restricting dislocation between the matrix and reinforcement interface.

In this study, 2014 Al matrix alloy reinforced with a 9 wt% of alumina (20 μm) particulates composites by novel two stage melt stirring (stir casting) practice used to synthesize, describe and analyze wear behaviour. Adding up of reinforcement was kept at 0 and 9wt%. For each wt. % preheated (i.e., 250°C) alumina particles were introduced in to the molten 2014Al alloy in steps of two by creating a vortex to overcome the clustering effects. Produced composite was examined by SEM analysis in support of exploring the microstructures and chemical components. Additionally characterization of wear studies of cast 2014Al matrix alloy and 2014Al-Al2O3 particulate composites were analyzed. After the assessment, it had been seen that there is an improvement in the hardness of the composites prepared and this is due to the incorporation of Al2O3 particulates in 2014Al alloy matrix meanwhile. Additionally, the wear rate of all composites prepared diminishes with increase in sliding distance while the wear rate of the composites prepared enhances with increase in load. By using Scanning Electron Microscope (SEM) the diverse wear mechanism for different test states of various compositions were examined.

In this paper an effort has made to develop and characterize Al7075 alloy reinforced with Tungsten carbide (WC) & Cobalt (Co). For uniform grain size and homogeneity of the reinforcements with matrix, Cermets (WC-Co) of grain size 50 microns were prepared with the help of ball milling operation. An experiment was conducted to evaluate the microstructure; mechanical properties like hardness test & tensile test as per the standards for different weight percentages of Cermets like 3, 6 and 9wt. %. Micrographs were studied to know the micro structure of the composite material and the result showed the, randomly dispersed reinforcement particles & fine interdendritic precipitates were seen. A comparative study was conducted for the microstructure and mechanical properties by using Cermets with varied weight percentages reinforced with Al7075 matrix. Mechanical properties results reveal that there is a considerable improvement in tensile strength and hardness as the percentage of Cermet increased from 3 to 9wt. %.

The present work aims at evaluating the grain refining performance of Al-7Ti master alloys with different microstructures on Al-7Si alloys. Al-7Ti master alloys were prepared in an induction furnace by salt route involving the reactions between K2TiF6 and molten Al. Reaction temperatures chosen for producing Al-7Ti master alloys were 800 0 C, 900 0 C and 1000 0 C while reaction time was kept constant at 60min..These indigenously prepared master alloys at different temperatures were characterized by chemical analysis; particles size analysis, XRD and SEM/EDX microanalysis. Results of particle size analysis suggest that mean size of Al3Ti intermetallic particles in Al-7Ti master alloys were increased from 15.8µm to 22.4 µm as temperature is increased from 800 0 C-1000

In this present work, an attempt has been made to optimize the wear properties of Al6061- SiC particulate composites. The composites containing 6 to 9 wt% of Silicon Carbide in steps of 3 wt% were prepared using liquid metallurgy route in particular stir casting technique. For each composite, reinforcement particles were preheated to a temperature of 300˚C and then dispersed in steps of two into the vortex of molten Al6061 alloy to improve the wettability and distribution. Dry sliding wear test method was used to conduct the experiments by using Ducom made pin-on-disc wear testing machine. Twenty seven experiments were carried out with the help of Taguchi L27 Orthogonal array. The influence of applied load, sliding speed and sliding distance on volumetric wear loss was estimated. Smaller the better parameter was chosen to optimize the wear process of prepared composites. Results show that applied load has the highest influence followed by speed and sliding distance.

In the present paper, wear behaviour of forged A356 alloy with and without grain refiner and or modifier has been investigated under dry sliding conditions using a pin-on-disc wear testing machine. Forging was carried on A356 alloy using a pneumatic power forging hammer of Model MS 412 for analyzing the wear properties. Wear experiments were carried out at various normal pressures, sliding speeds and sliding distances. The metallographic studies reveal that the forged samples have a more uniform distribution of the eutectic silicon in comparison to the as cast microstructures. The tribological results reveal that in forged condition a considerable decrease in the weight loss and frictional force was noticed as compared to the as cast A356 alloy and this would be due to the effect of forged and heat treated A356 alloy. Abrasive, oxidative, adhesive wear mechanisms are operative in different wear conditions.

Aluminum MMCs are preferred to other conventional materials in the fields of aerospace, automotive and marine applications owing to their improved properties like high strength to weight ratio, good wear resistance etc. In the present work an attempt has been made to synthesize metal matrix composite using 6061Al as matrix material reinforced with ceramic Al 2 O 3 particulates using liquid metallurgy route in particular stir casting technique. The addition level of reinforcement is being varied from 6-12wt% in steps of 3wt%. For each composite, reinforcement particles were preheated to a temperature of 200 °C and then dispersed in steps of three into the vortex of molten Al6061 alloy to improve wettability and distribution. Microstructural characterization was carried out for the above prepared composites by taking specimens from central portion of the casting to ensure homogeneous distribution of particles. Hardness and tensile properties of the prepared composite were determined before and after addition of Al 2 O 3 particulates to note the extent of improvement. Microstructural characterization of the composites has revealed fairly uniform distribution and some amount of grain refinement in the specimens. Further, the hardness and tensile properties are higher in case of composites when compared to unreinforced 6061Al matrix, also increasing addition level of reinforcement has resulted in further increase in both hardness and tensile strength.

In the current era of aerospace, automobile and other various industries, light weighed aluminium metal matrix composites plays a very major role. Metal matrix composites are composed of base material as metallic which is reinforced with ceramic particulate as reinforcement material. This paper consists of the preparation of micro composites by two step stir casting process by the addition of B4C particulates (80-90µm) into the AA2124 matrix by varying different weight percentages of 3% and 6% at a temperature of 730-750˚C. Further once the composites are prepared are subjected to characterization, the SEM revealed that there is good uniform distribution of micro particles in the aluminum by exhibiting a good bonding with matrix and EDS confirmed the presence of B and C elements. Different properties were evaluated like density, hardness, ultimate tensile strength and yield strength which revealed that there is an increase in the mechanical properties than compared to the base metal.

The present works manages readiness of the composites by mix stirring method. A356 amalgam 4 wt. % of B4C and A356-4 wt. % of Graphite and A356-4% B4C-4% Graphite hybrid composites were readied. To enhance the wetting and uniform conveyance of the particles, fortifications were preheated to a temperature of 500 Degree Celsius. The arranged MMCs are subjected to examining SEM instrument which affirms the homogenous uniform appropriation of smaller scale B4C and Graphite particles in the lattice combination without agglomeration. The wear protection of arranged composites was examined by performing dry sliding wear test utilizing DUCOM made stick on plate mechanical assembly. The tests were directed at a consistent heap of 3kg and sliding separation of 4000m over a speed of 100, 200 and 300 rpm. So also the other arrangement of investigations were led at consistent sped of 300 rpm and sliding separation of 4000m and with changing heap of 1kg, 2kg, and 3kg. The outcomes demonstrated that the wear protections of the composites were improved than the lattice material.

In this present work, systematic study has been conducted to investigate the wear phenomenon by adding micron size silicon carbide and graphite particles into Al6061 base. Al6061 compound was taken as the base lattice to which SiC and graphite particulates were utilized as fortifications. 6 wt. % of SiC and 6 wt. % of graphite were introduced to the base framework. The micostructural behaviour was analysed through scanning electron microscopy, which uncovered the uniform appropriation of SiC and graphite content in the Al matrix. Pin-on-disc equipment was utilized to assess the volumetric wear loss of arranged samples, in which EN32 steel disc was utilized as the counter face. The outcomes uncovered that the volumetric wear misfortune was expanded with increment in applied load, disc speed and sliding distance for every one of the specimens. The outcomes additionally showed that the volumetric wear loss of the Al6061-6% SiC-6% graphite composite was smaller than the Al6061 lattice. The worn out surfaces were portrayed by SEM analysis.

In the present work, binary Al–3Ti and Al–3B master alloys were prepared at different reaction temperatures in an induction furnace by the reaction of halide salts like potassium fluoborate and potassium titanium fluoride with liquid molten Al. The reaction temperatures of 800, 900 and 1000 °C were selected while the reaction time was kept constant at 60 min for the preparation of master alloys. These master alloys were characterized by chemical analysis, particle size analysis, XRD and SEM/EDX studies. The indigenously developed master alloys were used for grain refinement studies of Al–7Si alloy and evaluated for their grain refining ability by CA-CCA studies. The present results suggest that, the reaction temperature influences the size, size distribution and morphology of the intermetallic (Al 3 Ti in Al–3Ti and AlB 2 /AlB 12 in Al–3B) particles present in Al–3Ti and Al–3B master alloys. Grain refinement studies of Al–7Si alloy reveal that, Al–3Ti and Al–3B master alloys prepared at 800 °C–60 min have shown better grain refining efficiency on Al–7Si alloy when compared to the master alloys prepared at 900 °C–60 min and 1000 °C–60 min, respectively. In addition, B-rich Al–3B master alloy shows efficient grain refinement than Ti rich Al–3Ti master alloy.

Particulate reinforced aluminium matrix composites are being considered for their superior mechanical and tribological properties over the conventional aluminium alloys, and therefore, these composites have gained extensive applications in automotive and aerospace industries. In this investigation, the fabrication of 6061Al composites with different weight percentage of Al2O3 particles up to 0-9% was processed by liquid metallurgy route. For each composite, reinforcement particles were preheated to a temperature of 200°C and then dispersed in steps of three into the vortex of molten 6061Al alloy rather than introducing all at once, there by trying to improve wettability and distribution. Microstructural characterization was carried out for the above prepared composites by taking specimens from central portion of the casting. Microstructural characterization of the composites has revealed fairly uniform distribution of Al2O3 particulates. XRD analysis revealed the presence of Al2O3 and other phases. The tensile strength and hardness of the resultant composites were examined. It was revealed that the 6061Al- Al2O3 composites have a higher tensile strength than 6061 aluminium alloy with reduced ductility. It was found that an increase in the Al2O3 content in 6061Al alloy contributed in enhancing the hardness of the composites. The wear test was conducted using computerized pin on disc wear tester with counter surface as EN31 steel disc (HRC60) and the composite pin as specimens, demonstrated the superior wear resistance property of the composites.

In this investigation wear behaviour of A12219 alloy reinforced with SiC and graphite particulates were studied. The percentage of silicon carbide and graphite as reinforcements were varied from 2 wt.% to 4 wt.% in steps of 2. Energy dispersive spectroscopy and scanning electron microphotographs were used to confirm the presence of SiC and graphite particulates and its uniform distribution over the aluminum matrix. Wear behaviour of aluminum alloy Al2219 reinforced with silicon carbide and graphite fabricated by stir casting process was investigated. The wear properties of the metal matrix composites were studied by performing dry sliding wear test using a pin-on-disc wear tester. The experiments were conducted at a constant sliding velocity of 1.73m/s over a load of 2kg. The results showed that the wear resistance of Al2219-2%SiC-2% graphite and Al2219-4%SiC-4% graphite composites were better than the unreinforced alloy. The wear in terms of weight loss and wear rate was found to decrease with the increasing the weigh percentages of SiC and graphite. To study the dominant sliding wear mechanism worn surfaces were analyzed using scanning electron microscopy.

Aluminium metal matrix composites (AMMCs) are preferred because of their enhanced properties like high strength to weight ratio, stiffness and wear resistance. In the present work, an attempt is made to develop cermet (WC-Co) reinforced with Al7075 metal matrix composite by stir casting technique. WC-Co cermet is reduced to an average size of 10μm through ball milling using Alumina as grinding media. Ball milled WC-Co Cermet in an amount of 6 wt. % is used as reinforcement in Al7075 matrix. Microstructural characterization of the prepared composites is carried out using SEM/EDX and XRD studies. X-ray diffraction studies have revealed the peaks corresponding to α-Al, WC, Co and minor Al5W phases. SEM/EDX characterization revealed the uniform distribution of cermet in Al matrix. Further studies also revealed that, addition of WC-Co cermet to Al7075 matrix has resulted in improvement in hardness and Densities of Al7075 matrix.

Amongst advanced materials, metal matrix composites (MMC) are gaining importance as materials for structural applications in particular, particulate reinforced aluminium MMCs have received considerable attention due to their superior properties such as high strength to weight ratio, excellent low-temperature performance, high wear resistance, high thermal conductivity. The present study aims at studying and comparing the machinability aspects of B4Cp reinforced 6061Al alloy metal matrix composites reinforced with 37μm and 88μm particulates produced by stir casting method. The micro structural characterization of the prepared composites is done using Scanning Electron Microscopy equipped with EDX analysis (Hitachi Su-1500 model) to identify morphology and distribution of B4C particles in the 6061Al matrix. The specimens are turned on a conventional lathe machine using a Polly crystalline Diamond (PCD) tool to study the effect of particle size on the cutting forces and the surface roughness under varying machinability parameters viz., Cutting speed (29-45 m/min.), Feed rate (0.11-0.33 mm/rev.) and depth of cut (0.5-1mm). Results of micro structural characterization revealed fairly uniform distribution of B4C particles (in both cases i.e., 37μm and 88μm) in 6061Al matrix. The surface roughness of the composite is influenced by cutting speed. The feed rate and depth of cut have a negative influence on surface roughness. The cutting forces decreased with increase in cutting speed whereas cutting forces increased with increase in feed and depth of cut. Higher cutting forces are noticed while machining Al6061 base alloy compared to reinforced composites. Surface finish is high during turning of the 6061Al base alloy and surface roughness is high with 88μm size particle reinforced composites. As the particle size increases Surface roughness also increases.

The paper reports a study on wear properties of boron carbide reinforced Al metal matrix composite processed via stir casting route at lower temperature of 775 o C using halide salt K 2 TiF 6 with ratio 0.05Ti/B 4 C p to enhance better wettability. Fairly uniform distribution of B 4 C p in the matrix with no segregation is seen and revealed from SEM microphotographs. Micro hardness of the alloy and the composite was determined using Vickers micro hardness tester and found to increase with increase in volume fraction of B 4 C p addition to as cast 6061Al alloy. Pin-On-Disc tribometer was used to analyze wear behaviour of prepared composite and the alloy by applying normal load of 49.05m/s for a sliding velocity ranging from 3.34m/s - 10m/s up to a sliding distance of 565.4m at room temperature. Minimum wear rate was observed for 6061Al+ 6% B 4 C p at sliding velocity of 6.67m/s, normal load of 49.05N with sliding distance of 565.4N compared to 6061Al+ 4% B 4 C p composite and as cast 6061Al alloy. Worn surface were studied using optical microscopy to understand the wear mechanism exhibited by composites prepared.

A systematic study has been conducted to investigate the matrix properties by introducing nanosize ZrO2 (60-100 nm, 0.5–10 wt.%) fillers into an epoxy resin. High shear mixing process was employed to disperse the particles into the resin. The experimental results indicated that the frictional coefficient and wear rate of epoxy can be reduced at rather low concentration of nano-ZrO 2 . The lowest specific wear rate 0.1 x 10 -4 mm 3 /Nm is observed for the composites with 0.5 wt.% which is decreased by 95% as compared to the value of unfilled epoxy. Although the incorporation of nano-ZrO 2 particles leads to increased flexural modulus and flexural strength of epoxy, the wear performance of the composites does not correlate with these static mechanical properties. In contrast, there is a positive correlation between wear resistance and impact strength (i.e. increase in impact strength correlates with a decrease in specific wear rate).