Particulate Metal Matrix Composites Research Articles

Effect of solutioninzing and Ageing on Hardness of Aluminum LM13-MgO particulate metal matrix composite

Ceramic reinforced aluminum matrix composite materials are increasing wide acknowledgment in the designing application. Incorporation of MgO as reinforcement in aluminum LM13 Composite enhances its hardness. In the present examination aluminum LM13/MgO composites were produced by vortex strategy by shifting the weight level of MgO particulates from 0wt% to 10wt% in the means of 2wt%. The As-cast and its composites have been subjected to solutioninzing treatment at a temperature of 530° C for 2 hours, trailed by extinguishing in various media, for example, air, water and ice. The extinguished hardness examples were subjected to artificial aging at 164° C. Microstructural behavior were completed to comprehend nature of structure. The hardness test was led on both aluminum LM13 and aluminum LM13/MgO particulate composite, when warm treatment. Aluminum LM13/MgO particulate composites displayed critical change in hardness when contrasted and aluminum LM13.

Wear Behaviour of Heat Treated Aluminium LM13 –MgO Particulate Metal Matrix Composites

Wear Behaviour of Heat Treated Aluminium LM13 –MgO Particulate Metal Matrix Composites

Characterization of Glass Particulate Reinforced Aluminium Alloy6061 Metal Matrix Composites

In this paper an aluminum alloy Al6061- glass particulate metal matrix composites was prepared with different volume fraction of reinforcement 250 microns (3%, 6%, 9% and 12%) using melt stirring technique. The particle distribution in the prepared composites is observed using optical microscopy and XRD analysis. The prepared composite specimens were subjected to mechanical tests like hardness and tensile strength using Vickers hardness and uniaxial tensile testing instrument. It was observed from the results that the hardness and tensile strength increases with increase in wt% of reinforcement up to 9wt%. Hardness and tensile strength decreased for 12wt%.

Characterization and Effect of Particle Size On the Mechanical Properties of Glass Particulate Reinforced Aluminium Alloy6061 Metal Matrix Composites

In this research work, an attempt has been made to prepare Al6061- glass particulate metal matrix composites containing (3%, 6%, 9% and 12%) of glass particulates with four different particle sizes (75µm, 88µm, 105µm and 250µm) as reinforcement material were prepared using melt stirring method. The particle distribution in the prepared composites is observed using optical microscopy and XRD analysis. The prepared composite specimens were subjected to mechanical tests to evaluate the mechanical properties such as hardness and tensile strength using Vickers hardness and uniaxial tensile testing instrument. It was observed from the results that the hardness increase with an increase in wt% of reinforcement up to 9wt% and decreased for 12wt% for all particle sizes. Tensile strength increased with increase in wt% of reinforcement particle up to 9wt% and decreased for 12wt% for all particle sizes. Among the four particles sizes, 250µm particle size gives better mechanical properties.

Rutherford cable made of internal magnesium diffusion MgB2 wires sheathed with Al-Al2O3 particulate metal matrix composite

Rutherford MgB2 cable has been made from 12 single-core wires prepared via the internal magnesium diffusion process with a light outer sheath of Al-Al2O3 particulate metal matrix composite. Initially, critical currents of single-core wires with different diameters (between 1 mm and 0.465 mm) were measured. X-ray tomography was applied for the analysis of the uniformity of a Rutherford cable assembled of 0.465 mm strands. The obtained engineering current density at 4.2 K and 6. 5 T for the present cable (with only 9.6% of MgB2) is ∼3.6 times higher in comparison with a similar cable fabricated via the powder-in-tube in situ process with 19.8% of MgB2 phase. The strain tolerance of the cable by bending has shown a critical diameter of 70 mm. AC losses measured via the calibration-free method have shown apparently lower coupling losses for the cabled conductor. The obtained results are promising for future lightweight, mechanically flexible and low AC loss MgB2 superconductors suitable especially for motors or generators.

Modeling of Process Parameters for Surface Roughness and Analysis of Machined Surface in WEDM of Al/SiC-MMC

Wire electric discharge machining (WEDM) is a newly emerging non-traditional technology for machining MMCs. In the present study, an attempt has been made to investigate the effect of WEDM parameters such as pulse on time, pulse off time, peak current, spark gap voltage, wire feed rate and wire tension on the surface roughness height (Ra) during WEDM of particulate silicon carbide aluminum metal matrix composites (Al/SiC-MMC). The RSM based Box–Behnken design is employed for experimental investigation. Utilized the acquired results, a quadratic regression model for surface roughness height (Ra) has been developed. An attempt has been made to optimize the process parameters for surface roughness height (Ra). To validate, confirmation experiments have been carried out and predicted results have been found to be in good agreement with experimental findings. The surface morphology of machined surfaces has also been studied using scanning electron microscope. Various surface defects and their possible reasons have been discussed.

Fracture toughness investigations of Al6061-Graphite particulate composite using compact specimens

The objective of this research work is to study the fracture behavior of Al6061 with graphite particulate composite produced by the stir casting technique. For the study different composition of the particulate metal matrix composite used is Al6061 with 3, 6, 9, & 12% of graphite particles. Compact Tension (CT) specimens were utilized to determine fracture toughness for different compositions of Al6061-graphite particulate metal matrix composite. Specimens with different composition will be prepared for different crack length to width (a/w) ratios according to the ASTM E-399 standard testing procedure. The maximum fracture toughness was found for Al6061-9%Gr for a/w =0.45 and the value is 16.74 MPa ?m.

A Study on Cutting Force of Machining In Situ TiB2 Particle-Reinforced 7050Al Alloy Matrix Composites

In situ TiB2 particle-reinforced 7050Al alloy matrix composites are a new category of particulate metal matrix composites with improved mechanical and physical properties. At present, the study of machining in situ TiB2/Al composite is limited and no specific study has been presented on cutting force. Based on previous work, experimental investigation of cutting in situ TiB2/Al composite was carried out in this study to investigate the cutting force, shear angle, mean friction angle, and shear stress. The results indicated that the feed rate, instead of cutting speed, has a significant influence on the shear angle, mean friction angle, shear stress, and forces, which is different from cutting ex situ SiC/Al composites. Meanwhile, based on Merchant’s theory, a force model, which consists of chip formation and ploughing force, was established to have a better understanding of force generation. A comparison of the results show an acceptable agreement between the force model and experiments. Additionally, at varying feed rates, the linear relationship between the shear angle and mean friction angle is still suitable for cutting in situ TiB2/7050Al alloy composites.

Processing and characterization of Al-Al3Nb prepared by mechanical alloying and equal channel angular pressing

Mechanically alloyed Al with immiscible elements such as Nb can lead to a uniform distribution of nanoscaled precipitates which are highly stable compared to conventional alloying and with excellent interface, resulting in significant increase in strength without problems associated with nano ceramic particles in metal matrix composites. Although immiscible, Nb can be alloyed with Al through mechanical milling, forming trialuminide (Al3Nb), either directly or upon subsequent precipitation, which possesses high strength, stiffness and stability at elevated temperatures. In the present study, Al-5 at.% Nb supersaturated solid solution was achieved after prolonged ball milling and nano Al3Nb precipitates were formed during subsequent ageing at 530°C. The Al-Al3Nb powder was consolidated by equal channel angular pressing (ECAP) at 400°C, resulting in a fully dense material with a uniform distribution of nanoscaled Al3Nb precipitates in the Al matrix.

Interface diffusion-induced creep in metal matrix particulate composites under triaxial loading

Analytical solutions for interfacial diffusion-induced creep rate and stress relaxation in metal matrix particulate composites are developed under triaxial loading. Based on the Eshelby inclusion theory, the driving forces for interface diffusion and interface slip are obtained, respectively, and the relationship between them is clarified. The effects of the triaxial loading, the volume fraction of the inclusion, and the modulus ratio of the inclusion and matrix on the creep rate and stress relaxation are analyzed. In addition, the error caused by the scale effect is corrected by fitting the finite element results with the nonlinear least square method. The present solutions provide an important reference for various engineering applications of metal matrix particulate composites.

Numerical quantification of the impact of microstructure on the mechanical behavior of particulate Al/SiC composites in 2D

The objectives of the current manuscript are twofold: (i) Introducing an automated computational framework for creating realistic finite element models of metal matrix composites (MMCs) microstructures; (ii) Implementing this technique to investigate the effect of microstructure on the mechanical behavior of an Al/SiC particulate MMC. A microstructure reconstruction algorithm is proposed, which relies on the Centroidal Voronoi tessellation, together with the erosion, random movement, and iterative elimination of the resulting Voronoi cells to create an initial periodic virtual microstructure. Non-Uniform Rational B-Splines are also employed to capture the realistic shapes of embedded particles. High fidelity finite element models of the composite microstructure are then created using a non-iterative Conforming to Interface Structured Adaptive Mesh Refinement (CISAMR) technique. This integrated numerical framework is employed to analyze the effect of an Al/SiC MMC microstructure on its mechanical behavior, considering the plastic deformation of the Al matrix and damage in the SiC particles.

Metal-matrix composite fabricated with gas tungsten arc melt injection and precoated with NiCrBSi alloy to increase the volume fraction of WC particles

AbstractThe volume fraction, dissolution, and segregation of WC particles in metal-matrix composites (MMCs) are critical to their wear resistance. Low carbon steel substrates were precoated with NiCrBSi coatings and processed with gas tungsten arc melt injection method to fabricate MMCs with high volume fraction of WC particles. The microstructures and wear resistance of the composites were investigated. The results showed that the volume fraction of WC particles increased with decreasing hopper height and was as high as 44% when hopper height was 100 mm. The dissolution of WC particles was minimal. The content of the alloying elements decreased from the top to the bottom of the matrix. More WC particles dissolved in the overlapping area, where Fe3W3C carbide blocks could be found. The wear loss of the MMCs after 40 min was 6.9 mg, which is 76 times less than that of the substrate after the 4 min test.

Enhancement of Mechanical Properties of Graphite Particulate Aluminum Metal Matrix Composites by Magnesium Addition

In the present work effect of 1% Magnesium (Mg) addition on Graphite (Gr) particulate Aluminum metal matrix composites (AMMCs) has been studied. Achieving good wettability and uniform distribution of particles in the metal matrix are major challenges for the fabrication of metal matrix composites and this problem can be overcome by two step-mixing stir casting method. Literature suggests that Mg is a strong surface agent which removes oxygen from the dispersoids surface so gas layers (which are responsible for the poor wettability) will be reduced hence wettability between the reinforcement particles and metal melt will be improved. So to obtain good wettability of solid particles with Aluminum (Al) melt 1% Mg was added in the Gr particles. AMMCs were prepared by varying Gr content as 2, 4 and 6 weight percentage of Al with and without addition of Mg. By comparing both of the composites, it was observed that Gr-1 wt.% Mg admixture reinforced composites have better mechanical properties, better conductivity and better thermal stability than the unreinforced Mg composites and best results were obtained for 4 wt% of Gr-1 wt.% Mg admixture composite.

Producing AA1170 Based Silicon Carbide Particulate Composite through Stir Casting Method

Metal matrix composite (MMC) with improved thermal conductivity,abrasion resistance, tribology, creep resistance, dimensional stability,good stiffness-to-weight and strength-to-weight ratio will find application in the aerospace, automobile, mechatronics components (suchas sensor) and other engineering outfits. In the present work, the aim is to develop aluminum (AA1170) based silicon carbide particulate metal matrix composites with an objective to develop a conventional low-cost method of producing MMC's, and to obtain homogenous dispersion of silicon carbide. To achieve these objectives two stepmixingmethods of stir casting technique has been used. AA1170 and SiC (3, 9, 29 and 45 μm grit sizes) have been chosen as matrix and reinforcement materials respectively. Experiments have been conducted by varying weight fraction of SiC (2.5, 5.0, 7.5 and 10%). The results indicated that the stir casting method is quite successful in obtaining uniform dispersion of reinforcement in the matrix.Measured properties of aluminium silicon carbide (composite) showed increase in young's modulus (E) and hardness above the unreinforced aluminium, however, there was marginal reduction of electrical conductivity in the composite

Fabrication of Aluminium Metal Matrix Composites with Particulate Reinforcement: A Review

This paper presents a summary of work reported on Aluminium metal matrix composites with particulate reinforcement. Aluminium metal matrix has growing demand in aircraft, automotive and other industries due to its light weight, high strength to weight ratio, corrosion resistance and workability. Particle reinforced aluminium matrix composites are preferable due to their reduced cost, uniform properties, and their ability to be like monolithic materials. Although numerous method are available to fabricate the particulate metal matrix composite, stir casting is the most preferable one due to its cost effectiveness and convenience. Present paper reviews the problems taken and results obtained by various authors who have contributed in the area of Aluminium metal matrix composites with particulate reinforcement through stir casting. The reported works reveal that decrease in particle size and increase in percentage addition of reinforcement increase hardness and tensile strength of the composite.

Characterization of waste eggshells and CaCO3 reinforced AA2014 green metal matrix composites: A green approach in the synthesis of composites

Three AA2014 alloy metal matrix composites containing reinforcing particles of eggshell, carbonized eggshell and CaCO3 (powder) were processed. The influences of different particle percentage of eggshell were compared with commercial calcium carbonate. The electromagnetic stir casting technique followed by hot extrusion was employed to fabricate metal matrix composite. The results revealed that the tensile strength, hardness and fatigue strength increased by the addition of eggshell particles up to 12.5 wt.% in AA2014 matrix alloy for both carbonized and uncarbonized reinforced composites. Toughness, ductility and corrosion rate decreased by the addition of eggshell particles up to 12.5 wt.% in AA2014 matrix alloy for both carbonized and uncarbonized reinforced composites. Mechanical properties decreased in the addition CaCO3 in AA2014 matrix alloy. After the heat treatment process, mechanical properties further improved for both carbonized and uncarbonized eggshell particles reinforced composites. However, corrosion rate increased. These results showed that using the carbonized eggshell as reinforcement in the AA2014 alloy gave better physical and mechanical properties at lower cost as compared to uncarbonized ES particles and CaCO3. Apparent interfacial reaction layer and minimum corrosion were observed at AA2014/12.5% carbonized eggshell particulate composite. No reaction product was observed at AA2014/CaCO3 particulate metal matrix composite.

DEVELOPMENT AND TRIBOLOGICAL PROPERTIES OF PARTICULATE MMC DEVELOPED BY STIR CASTING PROCESS

The present work concentrates on development of particulate metal matrix composite using Aluminum alloy (AL 7075) as the matrix material and alumina(Al2O3), Silicon Carbide (SiC) and Hybrid (Al2O3+SiC) as Reinforcement.Al2O3 is reinforced in the weight fraction of3%, 6%, 9% and 12% with the particle size varying between 50 microns to 150 microns. SiC in the weight fraction of 3%, 6%, 9% and 12% & Al2O3+SiC in the weight fraction of 3%+3%, 6%+3%, 9%+3% and 12%+3%. The aluminum alloy was melted at 700°C in an electrical heating furnace for 20 minutes and the reinforcement is heated separately at 350° C was added in the form of powder. The mixture was stirred for 5 minutes at the temperature of 650°C, then poured in to the sand mold. Optical micro graph of the developed composite was obtained to demonstrate the distribution of the reinforcement in the matrix. The hardness tests was carried out to determine the effect of reinforcement on the hardness of the composites. It is observed that the hardness of the composite increases with the increase in weight fraction of the reinforcement. The wear test carried out at various speed, load and sliding distance which indicates improvement in the mechanical properties of the composites. The wear resistance of the composite was found to reduce with the increase in the weight fraction of the reinforcement. The wear resistance was found to decrease with increase in speed, but it increases with the increase in load and sliding distance for all specimens. The coefficient of friction was found to decrease with the increase in weight fraction of the reinforcement. The noise during running the test was reduced in case of Hybrid composite as compared to composite with either alumina or silicon carbide as reinforcement. The investigation carried out will lead to development of the composite system with high strength, improved wear resistant, light weight for automobile parts like disc brake, piston, cylinder liner, drive shaft etc.

Role of powder preparation route on microstructure and mechanical properties of Al-TiB2 composites fabricated by accumulative roll bonding (ARB)

Accumulative roll bonding (ARB) was conducted up to seven cycles to fabricate Al-TiB2 particulate metal matrix composites. The reinforcing particles were prepared and used in three different processing conditions: as-received TiB2, mixed TiB2-Al and in-situ synthesized TiB2-Al. The mixed TiB2-Al powder was produced by milling of TiB2 with Al powder and in-situ synthesized TiB2-Al powder was prepared by mechanical alloying (MA) through inducing TiB2 particles in the Al with various composition of 10, 20 and 30wt% Al. Transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to evaluate the microstructure of the produced composites. The composite obtained from the in-situ TiB2-Al powder showed the most uniform distribution of particles and exhibited the highest tensile strength of about 177MPa in comparison with the composites reinforced with the as-received TiB2 (156MPa) and mixed TiB2-Al powder (160MPa). After seven ARB cycles, an ultra-fine grained structure with the average size of about 300nm was obtained in the composite reinforced with in-situ TiB2-Al powder. The appearance of dimples in tensile fracture surfaces revealed a ductile-type fracture in the produced composites.

Mechanical and metallurgical characterizations of AA2014/eggshells waste particulate metal matrix composite

Chicken eggshell (ES) is an aviculture byproduct that has been listed worldwide as one of the worst environmental problems. The effective utilization of chicken eggshell (ES) biowaste is strongly encouraged in our society for environmental and economic reasons. The present work deals with development of AA2014/carbonized eggshells particulate composites by electromagnetic stir casting process at optimized parameters using RSM. The predicted tensile strength of 239 MPa of the composite was found at optimum parameters of 60 MPa (Squeezing Pressure), 12 ampere (Current), 180 s (Time) and 700°C (Pouring Temperature) respectively. There was about 2.79% error in the experimental and modeled results of tensile strength. Obtained result shows that as stirring current and stirring temperature increases, tensile strength also increases. While increase in pouring temperature of matrix decreases tensile strength of composite. Density of the metal matrix composite decreases 5%, when eggshells particulate is added 5% by wt. to matrix alloy. Hardness, toughness and fatigue strength were also carried out of the AA2014/eggshell composite. Results show an improvement in these properties with the addition of eggshell in the matrix alloy. Microstructural study show uniform distribution of eggshell in the composites.

Effect of Heat Treatment on the Microstructure, Hardness and Wear Properties of Al−15Mg<sub>2</sub>Si−3Cu with Different Contents of Zn

The effects of heat treatment (T6) on the microstructure and dry sliding wear behavior of Al- 15Mg2Si-3Cu particulate metal matrix composite (PMMC) with different contents of Zn have been investigated. The composite was characterized by scanning electron microscopy equipped with energy dispersive spectrometer (EDS). Dry sliding wear experiment was performed in a pin-on-disc wear tester against a DIN 100Cr6 steel disc at a speed of 220 rpm using normal load of 30N. Results show that increasing the Zn content causes a significant improvement in hardness. This is ascribed to the observed increase in matrix strength due to the formation of Al-Zn solid solution in the matrix. Zn was also found to be powerful in increasing wear resistance. The wear results showed that abrasion is the dominant wear mechanism in the composite containing 15 wt.% Zn, whilst a combination of adhesion and delamination appears to be the governing mechanism for as-cast composites.