Hybrid Aluminium Matrix Composites Research Articles

Fabrication and Characterization of Silicon Carbide and Fly Ash Reinforced Aluminium Metal Matrix Hybrid Composites

Aluminium metal matrix composites with multiple reinforcements (hybrid metal matrix composites) have great potentials of satisfying recent demands of advanced engineering applications due to their improved mechanical properties such as hardness, stiffness, ultimate tensile strength, toughness etc. The performance of these materials mostly depends upon selecting right combinations of reinforcing materials. The present research study deals with the fabrication and characterization of 6082 Aluminium matrix hybrid composites reinforced with Silicon Carbide (SiC) and Fly Ash. Stir casting method is used to fabricate aluminium metal matrix composites reinforced with different weight fractions of 2.5, 5 and 7.5% SiC and Fly Ash in equal proportions. The microstructural characteristics of composites are studied with the help of Scanning Electron Microscopy (SEM). Mechanical properties such as ultimate tensile strength, hardness are studied and compared with the results of unreinforced Aluminium alloy. The dry sliding wear behavior of composites is studied by using pin-on-disc wear testing machine and the results are compared with results of unreinforced Aluminium alloy. It is found that there is a good improvement in ultimate tensile strength, hardness and wear properties with the increase in weight fraction of reinforcements of SiC and Fly Ash in a aluminium matrix hybrid composites.

Optimization of Wire EDM Process Parameters for Machining Hybrid Composites (356/B4C/Fly Ash) using Taguchi Technique

Aluminium matrix composites (AMCs) are a class of advanced materials which have been developed for weight-critical applications. In addition they can be fabricated using conventional methods. In this study 356 Aluminium alloy is used as the matrix material for fabrication of hybrid AMCs by stir casting. Hybrid AMCs containing 1.5%, 3% & 4.5% boron carbide of average particle size 63 µm and 1.5%, 3% & 4.5% fly ash of average particle size 12 µm were fabricated. Optical micrographs of the composites show that the reinforcement particles were uniformly distributed in the matrix. WEDM is used to cut conductive materials of any hardness that are difficult or impossible to cut with traditional methods. WEDM is specialized in cutting complex contours or fragile geometries. High material removal rate and good surface finish cannot be achieved simultaneously. This is an important problem and continuous efforts are being made by various researchers all over the world. This research work attempts to develop an appropriate machining strategy for WEDM of hybrid AMCs using 0.25 mm diameter brass wire as the electrode. The five important process parameters such as gap voltage, pulse on time, pulse off time, wire feed and percentage reinforcement are taken as input parameters and material removal rate as the output parameter. The experiments have been carried out using the Taguchi’s L27 orthogonal array and analyzed using Signal to Noise (S/N) ratio analysis for finding the optimum process parameters. Analysis of Variance (ANOVA) is used to find the percentage contribution of the parameters and that of their interactions. The S/N ratio analysis results show that the gap voltage is the most significant parameter for obtaining higher MRR, followed by pulse on time and pulse off time. The parameters reinforcement and wire feed have no significance, since WEDM can cut material of any hardness.

Experimental investigation and optimization of multiple performance characteristics of Al-Mica-B4C hybrid reinforced composite in drilling operation

Machining of composite is critical task and many parameters are needed to study in order to evaluate the performance of composite. In present study, performance characteristics of Al- mica-B4C composite are evaluated and optimized with Taguchi-grey relational analysis in drilling of B4C and mica reinforced hybrid aluminium matrix composites (AMCs) manufactured by powder metallurgy process. HSS, TiAlN coated carbide drill bits and uncoated cementide carbide drills bits were used under dry cutting conditions. The drilling parameters such as feed rate, spindle speed, drill tool material and material parameters like wt. % of B4C as well as Mica particles were optimized based on multiple performance characteristics including thrust force, drilling torque and surface roughness. Experiments were conducted on a computerised numerically controlled vertical machining centre. Drilling tool dynamometer is used to measure the thrust force and drilling torque. Also, to measure the surface roughness of drilled hole portable surface roughness tester is used which shows the readings in microns. Microstructure of composites and surface morphology of drilled hole is studied by using optical microscopy. Finally, it is concluded that, among the drilling tools used, TiAlN coated carbide drill bit shows the better result than other drill bits used. Composites manufactured in present study shows better strength for all levels of reinforcement. Also, it is found that the drilling feed rate affects on the drilling process significantly.

Hybrid aluminium matrix composites containing boron carbide and quasicrystals: manufacturing and characterisation

ABSTRACTHybrid composites of boron carbide (B4C) and Al62.5Cu25Fe12.5 quasicrystals (QCs) were prepared by ball milling and pressureless sintering in aluminium matrix to investigate their individual and hybrid effects on microstructural and mechanical properties. Hybrid composite contained B4C and QCs in 3 wt-% each, making a total of 6 wt-%. For reference, specimens of pure aluminium and two composites containing 6 wt-%B4C and 6 wt-% QCs were prepared. Microstructural characterisation was performed using optical, scanning electron microscopy and X-ray diffraction, while evaluation of mechanical properties was carried out by hardness and compression tests. Uniform dispersion of reinforcements in composites was observed along with significant increase in the mechanical properties. The composite containing 6 wt-% QCs demonstrated the highest hardness, while the hybrid composite showed better compressive properties.

Microstructural and mechanical characterization of hybrid aluminum matrix composite containing boron carbide and Al-Cu-Fe quasicrystals

Hybrid aluminum matrix composites containing particles of boron carbide and quasicrystals were manufactured to explore the combined effect of reinforcements on microstructural evolution and mechanical performance of the composites. The particles were incorporated at a loading of 6 wt% each making a total of 12 wt% reinforcement in pure aluminum. For comparison, two composites containing individually reinforced 12 wt% particles were also prepared along with a reference specimen of pure aluminum. Ball milling technique was employed to mix the composite constituents. The green bodies of composite powders were prepared by uniaxial pressing at room temperature followed by consolidation by pressureless sintering under inert atmosphere. The microstructural characterization was performed using scanning electron microscopy while phase identification was carried out by X-ray diffraction. The mechanical characterization was performed by Vickers hardness and compression tests. Hybrid composites showed increased compressive properties while the composites containing solely quasicrystals demonstrated improved hardness. The increase in mechanical performance was related to the microstructural evolution due to the presence and uniform dispersion of binary particles.

Optimization of Stirring Parameters Using CFD Simulations for HAMCs Synthesis by Stir Casting Process

Hybrid aluminum matrix composites (HAMCs) are capable to meet recent demands of advanced engineering applications due to its tunable mechanical properties and lower cost. Stir casting is one of the prominent and economical method for processing of continuous reinforced HAMCs. In this method, flow pattern is the key factor for distribution of particles in the molten metal. Effective flow pattern can be achieved by optimizing stirring parameters i.e. blade angle, impeller size and stirring speed. However, complete study and optimization of flow is a challenge for research community. Finite element method simulation along with optimization technique is one of the effective combination to guide experimental research. In this paper, computational fluid dynamics has been used to simulate fluid flow during stir casting, whereas optimization of stirring parameters is done by Grey Taguchi method. Optimized parameters have been used for experimental synthesis of HAMCs. Furthermore, optical micrograph and hardness confirms about the uniform dispersion of reinforcements. These results may guide the researchers for the preparation of HAMCs with uniform particle distribution by stir casting route for industrial applications.

Fabrication of aluminium matrix hybrid composites reinforced with SiC microparticles and TiB2 nanoparticles by powder metallurgy

ABSTRACTIn this study, aluminium matrix hybrid composites (AMHCs) containing 10 wt-%SiC microparticles and wt-%TiB2 ( = 1, 3 and 5) nanoparticles were fabricated by powder metallurgy. The effect of TiB2 content on microstructure and mechanical properties were examined by a combination of scanning electron microscopy, transmission electron microscopy and tension tests. The results showed that mechanical properties of the hybrid composites were improved with increasing the content of TiB2 nanoparticles. Compared to aluminium matrix composites reinforced with mono SiC microparticles, the ultimate tensile strength and yield strength of the AMHCs with additional 5 wt-% TiB2 nanoparticles were increased by 64 and 23%, respectively. Based on the fractographs, the relevant fracture mechanism was also discussed.

The Effect of Production Process Parameters on the Tensile Strength of Squeeze Cast Al2O3+SiC/Al6061 Hybrid Composites

Abstract This study investigated the conditions for the optimal performance of hybrid aluminum matrix composites produced by squeeze casting. The significant die casting parameters chosen for analysis were the squeeze pressure (50, 70, 90 MPa); die preheat temperature (100, 200, 300°C) and duration of pressurization (15, 30, 45 s). Composites containing 10 and 20 % volume fractions of reinforcements were synthesized by infiltrating molten aluminum alloy 6061 into prefabricated porous preforms composed of Al2O3+SiC microparticles. Experiments were conducted by implementing the L933 orthogonal design of Taguchi, where the objective function was to maximize the tensile strength of the castings by appropriate statistical analysis. The results suggested that the production process was successful as the microparticles were evenly distributed within the matrix alloy. The control parameters of squeeze pressure and duration of pressurization were found to be the most significant factors influencing the tensile strength of the castings. As the volume fraction of reinforcements increases in the composites, the duration of pressurization is the most critical factor to enhance the tensile strength. The optimal control settings required to maximize tensile strength were specified with respect to the volume fraction of reinforcements content. The data from statistical experimental design was compared with mathematical predictions and through verification tests, these results were found to be in close agreement.

Dry sliding wear studies of aluminum matrix hybrid composites

In the present work, hybrid composites are fabricated with self-lubricating characteristics to make them as resource-efficient materials.AA6061-10 wt. % B4C–MoS2 hybrid composites reinforced with 2.5, 5 and 7.5 wt. % concentration of MoS2 particles are produced using stircasting technique, and mechanical and tribological properties are evaluated. Microstructural characterization of the hybrid composites revealed theuniform distribution of reinforcement (B4C and MoS2) particles in the matrix material. Hardness and fracture toughness of the hybrid compositesare decreased monotonously with an increase in the addition of MoS2 particles. Dry sliding tribological studies conducted using a pin-on-disktribotester under atmospheric conditions revealed the formation of MoS2-lubricated tribolayer on the worn pin surface which significantlyinfluenced the tribological properties. The addition of MoS2 particles decreased the friction coefficient and wear rate of the hybrid composites.Delamination and abrasion are observed to be the controlling wear mechanisms and material in the form of platelet-shaped debris, and flow-typechip debris is formed, and a long and shallow crater on the worn pin surface of the hybrid composite is also observed.

Dry sliding wear studies of aluminum matrix hybrid composites

Abstract In the present work, hybrid composites are fabricated with self-lubricating characteristics to make them as resource-efficient materials. AA6061-10 wt. % B 4 C–MoS 2 hybrid composites reinforced with 2.5, 5 and 7.5 wt. % concentration of MoS 2 particles are produced using stir casting technique, and mechanical and tribological properties are evaluated. Microstructural characterization of the hybrid composites revealed the uniform distribution of reinforcement (B 4 C and MoS 2 ) particles in the matrix material. Hardness and fracture toughness of the hybrid composites are decreased monotonously with an increase in the addition of MoS 2 particles. Dry sliding tribological studies conducted using a pin-on-disk tribotester under atmospheric conditions revealed the formation of MoS 2 -lubricated tribolayer on the worn pin surface which significantly influenced the tribological properties. The addition of MoS 2 particles decreased the friction coefficient and wear rate of the hybrid composites. Delamination and abrasion are observed to be the controlling wear mechanisms and material in the form of platelet-shaped debris, and flow-type chip debris is formed, and a long and shallow crater on the worn pin surface of the hybrid composite is also observed.

Wear Behavior of Aluminum Matrix Hybrid Composites Fabricated through Friction Stir Welding Process

Effects of friction stir processing (FSP) parameters and reinforcements on the wear behavior of 6061-T6 based hybrid composites were investigated. A mathematical formulation was derived to calculate the wear volume loss of the composites. The experimental results were contrasted with the results of the proposed model. The influences of sliding distance, tool traverse and rotational speeds, as well as graphite (Gr) and titanium carbide (TiC) volume fractions on the wear volume loss of the composites were also investigated using the prepared formulation. The results demonstrated that the wear volume loss of the composites significantly increased with increasing sliding distance, tool traverse speed, and rotational speed; while the wear volume loss decreased with increasing volume fraction of the reinforcements. A minimum wear volume loss for the hybrid composites with complex reinforcements was specified at the inclusion ratio of 50% TiC + 50% Al2O3 because of improved lubricant ability, as well as resistance to brittleness and wear. New possibilities to develop wear-resistant aluminum-based composites for different industrial applications were proposed.

Fabrication characteristics and tribological behavior of Al/SiC/Gr hybrid aluminum matrix composites: A review

Abstract Improvement in surface properties and retainment of bulk properties are essential requirements for the design of components for wear resistance applications. This paper summarizes various features of Al/SiC/Gr hybrid composites that can be employed in different tribological applications. The study has revealed that the processing route plays a significant role in obtaining a homogeneous structure of these composites. In powder metallurgy, the selection of sizes of the matrix and reinforcement powders is crucial, whereas the wettability between the reinforcement particles and molten alloy is a major challenge in liquid metallurgy. The incorporation of SiC particles increases the mechanical strength and wear performance of Al composites. However, ejection of these particles can reduce the wear performance of Al composites under severe conditions. The addition of Gr particles helps in the formation of a thick and extensive tribolayer on the wear surface. This layer reduces direct contact between the rubbing surfaces, thereby decreasing the wear rate under certain conditions. Morphological analysis of worn surfaces has confirmed that the hybrid composites exhibit superior wear properties than the pure Al alloy and the ceramic-reinforced composite. However, increase in the Gr content beyond a limiting value can deteriorate the tribological properties of these composites. Therefore, true optimization of a tribosystem (of the hybrid composite and counterface) can be achieved by selecting appropriate reinforcement contents.

Investigation of Effect of Graphite Particles on Drillability of Metal Matrix Composite

The present article investigates the effect of graphite particles in the drilling of hybrid aluminium matrix composites (AMCs) using TiN coated carbide drills. Materials used for the present investigation are Al6063-aluminum alloy reinforced with alumina of size 20 microns and graphite of an average size 75 microns, which are produced through stir casting method. Experiments are conducted based on Taguchi’s method L27 orthogonal array on a vertical machining centre. A model is developed to correlate the drilling parameters with burr height and surface roughness using regression analysis. The results indicate that the developed model is suitable for prediction of burr height and surface roughness in drilling of hybrid AMCs.The influence of different parameters on Surface roughness and burr height of Al6063/Al2O3p/Grp composites has been analyzed through ANOVA table and contour graphs.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.9724

Study of hardness and tensile strength of Aluminium-7075 percentage varying reinforced with graphite and bagasse-ash composites

Waste sugarcane bagasse-ash and graphite utilizing as reinforcement in fabricating of an aluminium alloy (Al-7075) based matrix hybrid composites. The aluminium matrix hybrid composites have been fabricated by stir-casting method at 750 °C. Casting was developed in circular metal mould having 5 circular slots of diameter of 21 mm and length of 250 mm. Adding bagasse-ash with varying reinforcement of three cases, in first case 2% constant with varying graphite 1%, 3%, and 5%, in second case 4%, and in third case 6% constant with varying same graphite percentage. The effect of the reinforcement has been performed through various mechanical tests. The mechanical properties measuring such as Brinell hardness and tensile strength of both the samples have been prepared as per the ASTM E23 and E8 standards. Results give out that there will be greater effect of reinforcing different bagasse-ash in aluminium alloy matrix hybrid composites. In the third case more enhanced mechanical properties have been achieved as compared to case one and two of bagasse–ash combination. It shows that the selection of bagasse-ash as reinforcement has one of the most significant criteria for the fabrication of aluminium matrix hybrid composites.

Study of hardness and tensile strength of Aluminium-7075 percentage varying reinforced with graphite and bagasse-ash composites

Abstract Waste sugarcane bagasse-ash and graphite utilizing as reinforcement in fabricating of an aluminium alloy (Al-7075) based matrix hybrid composites. The aluminium matrix hybrid composites have been fabricated by stir-casting method at 750 °C. Casting was developed in circular metal mould having 5 circular slots of diameter of 21 mm and length of 250 mm. Adding bagasse-ash with varying reinforcement of three cases, in first case 2% constant with varying graphite 1%, 3%, and 5%, in second case 4%, and in third case 6% constant with varying same graphite percentage. The effect of the reinforcement has been performed through various mechanical tests. The mechanical properties measuring such as Brinell hardness and tensile strength of both the samples have been prepared as per the ASTM E23 and E8 standards. Results give out that there will be greater effect of reinforcing different bagasse-ash in aluminium alloy matrix hybrid composites. In the third case more enhanced mechanical properties have been achieved as compared to case one and two of bagasse–ash combination. It shows that the selection of bagasse-ash as reinforcement has one of the most significant criteria for the fabrication of aluminium matrix hybrid composites.

Influence of boron nitride nanoparticles on microstructure and wear behavior of AA6082/TiB2 hybrid aluminum composites synthesized by friction stir processing

Friction stir processing (FSP) was successfully applied to synthesize AA6082/(TiB2+BN) hybrid aluminum matrix composites (AMCs) and compared with AA6082, AA6082/TiB2 AMC and AA6082/BN AMC. TiB2 and BN particles were compacted into a groove and FSP was carried out at optimized parameters. The microstructure was investigated by optical, scanning electron and transmission electron microscopy. Sliding wear behavior was evaluated using a pin-on-disc apparatus. Micrographs revealed a homogenous dispersion of particles in the aluminum matrix irrespective of the region within the stir zone. There was no segregation of two type particles in the hybrid AMC. Effective interfacial bonding between the particles and the aluminum matrix was demonstrated with extensive grain refinement occurring in the matrix. The shape and morphology of the TiB2 particles altered during FSP while the BN particles were intact. The addition of BN nanoparticles enhanced the wear resistance of AA6082/TiB2 AMC by acting as a solid lubricant and forming a tribo film. The wear mode changed with the addition of TiB2 and BN as dispersed particles. BN particles reduced the iron content in the wear debris of AA6082/TiB2 AMC which is beneficial for a reduction in counterface wear.

Influence of hybrid ratio and friction stir processing parameters on ultimate tensile strength of 5083 aluminum matrix hybrid composites

Abstract In this study, effects of friction stir processing (FSP) parameters and hybrid ratio on the ultimate tensile strength (UTS) of aluminum (Al) matrix (5083) hybrid composites (AMHCs) were investigated in detail. In order to estimate the ultimate tensile strength of the prepared composites, a mathematical formulation was derived, and test results were compared with those of the model. The effects of factors influencing strength, such as tool rotational and traverse speeds, and volume fractions of, carbon nanotube (CNT), aluminum oxide (Al 2 O 3 ), graphite (Gr), silicon carbide (SiC) and zirconium oxide (ZrO 2 ) were also studied using the proposed formulation. Test results showed that the ultimate tensile strength of these composites significantly increased with increasing CNT, tool rotational and traverse speeds. In addition, the effects of complex reinforcements with different volume fractions on the 5083 AMHCs were examined. A maximum tensile strength for the hybrid composite was found at the inclusion ratio of 10% Gr + 5% ZrO 2 . This study may open up new possibilities to developing highly strength Al alloys for various industrial applications.

Production and characterization of AA6082-(Si3N4 + Gr) stir cast hybrid composites

ABSTRACTThe present research work emphasizes the development of hybrid aluminum (AA6082) matrix composites (HAMCs) reinforced with different weight percentages (wt.%) of ball-milled (silicon nitride (Si3N4) + graphite (Gr)) ceramic particulates by conventional stir casting process. Si3N4 and Gr are ball milled to obtain a definite density of combined powder. The weight percentage of ball-milled ceramic powder is varied from 0 to 12 wt.% in a stage of 3%. The microstructures as well as mechanical properties of the fabricated hybrid composites are analyzed. The scanning electron micrograph reveals the uniform distribution of ball-milled (Si3N4 + Gr) ceramic particulates in the aluminum matrix. The distribution of ball-milled (Si3N4 + Gr) ceramic particulates has also been analyzed with x-ray diffraction (XRD) technique. Both the hardness and ultimate tensile strength have enhanced with a reduction in percentage elongation with increase in weight percentage of ball-milled (Si3N4 + Gr) ceramic particulates in the aluminum matrix.

Optimization of cutting parameters and graphite rate in drilling of a hybrid aluminium matrix composites

Optimization of cutting parameters and graphite rate in drilling of a hybrid aluminium matrix composites

Preparation and Characterization of Hybrid Aluminum Matrix Composites Reinforced with MWCNT Using Powder Metallurgy Process

Metal Matrix Nano Composites (MMNC) consist of a metal matrix reinforced with nano-particles featuring physical and mechanical properties very different from those of the matrix. Especially carbon Nano tubes (CNT) can improve the matrix material in terms of wear resistance, damping properties and mechanical strength. The present investigation deals with the synthesis and characterization of aluminium matrix reinforced with micro B4C particles, and Multi Wall Carbon nano Tubes (MWCNT) were prepared by powder metallurgy route. Powder mixture containing fixed weight (%) of B4C and different wt% of MWCNT as reinforcement constituents that are uniaxial cold pressed and later green compacts are sintered in continues electric furnace. Microstructure and Mechanical properties such as micro hardness and density are examined. Micro structure of samples has been investigated using scanning electron microscope (SEM) .The results indicated that the increase in wt % of MWCNT improves the bonding and mechanical properties.