Particle Reinforced Metal Matrix Composites Research Articles

Effect of Variations in Microwave Processing Temperatures on Microstructural and Mechanical Properties of AA7075/SiC/Graphite Hybrid Composite Fabricated by Powder Metallurgy Techniques

Due to the demand in present industrial, aerospace, defense sectors for lightweight high-performance aluminum (Al) particle-reinforced metal matrix composites, the advancement of techniques to fabricate these composites with superior mechanical properties have gained technological interest in the modern world. In this direction, SiC and graphite reinforced AA7075 matrix composite material has been fabricated in this study, through hybrid microwave sintering techniques. The microwave sintering temperatures for the optimized volume fraction composition of AA7075/SiC/graphite hybrid composite has been varied from 400 to 550 °C with a step value of 50 °C. The obtained results showed a superior improvement in the mechanical properties for microwave sintered composites as compared to the conventionally sintered composites. Mechanical properties are found to show increasing trend with increasing microwave sintering temperatures up to 500 °C, after that, a downfall is observed in their mechanical properties, which can be attributed to the increased average grain size of the composite at 550 °C. Selection of SiC as primary reinforcement material helped in achieving high mechanical strengths, and through microwave sintering, an increment of 37.2% in tensile, 26.6% in compression, and 16.5% in hardness is achieved. From this investigation, it is also observed that the selection of materials that shows high response to microwaves helps in achieving the enhanced mechanical properties for the hybrid composites processed by microwave sintering techniques.

Effect of reinforcement on microstructure and mechanical properties of aluminium hybrid composites

Al based metal matrix composites are widely used in aerospace and automobile and engineering applications where high strength to weight ratio and good corrosion resistance are of prime importance. In the present investigation SiC/Al2O3 and SiC + Al2O3 particulate reinforced metal matrix composites with varying weight percent of SiC, Al2O3 and SiC + Al2O3 (2,4,6) were produced by a stir casting process. An optical microscope was used to examine the morphology of dendrites and distribution of reinforcement at varying magnification. The porosity content was measured by comparing the theoretical and experimental determined by Archimedean method. Bulk (Brinell hardness test) and Micro(Vickers Hardness test)hardness tests were done. Brinell hardness test has advantage of covering larger area and hence it incorporates all microstructural heterogeneity whereas microhardness gives information abour interface bonding strength between reinforcement and matrix. The results indicated that in case of SiC reinforcement, there is increase in porosity with increase in wt. % of SiC particles and in case with Al2O3 exceptionally high porosity (%) with 4 wt% Al2O3 due to error during casting. However, in case of hybrid (SiC + Al2O3) composite there is increase in microhardness, Brinell hardness, compared to unreinforced A356 alloy and mono composites.

Cutting deformation mechanism of SiCp/Al composites based on strain gradient theory

More and more experiments have shown that particle-reinforced metal matrix composites (PMMC) exhibit obvious size effects. The aclassic plasticity theory does not contain internal length scale and cannot explain this size effect. In this paper, based on the Taylor relationship, the concept of "geometrically necessary dislocations" and the mechanism of dislocation multiplication, slippage and extinguishing, a constitutive equation for SiCp/Al composites related to strain gradient is established. The established equation is imported into Abaqus for simulation by writing a user subroutine Vumat. Combining the simulation and experimental results, the effects of stress, temperature, cutting force, strain gradient effect and its dimensional effect on cutting deformation during machining SiCp/Al composites are analyzed from the perspectives of material micro-plasticity mechanics and material dislocation theory. The results show that the presence of SiC particles changes the microstructure of the matrix material, and induce a high strain gradient in the matrix. This high strain gradient makes the material more prone to shear deformation localization. In the cutting process, the defects and breakage of the SiC particles themselves will lead to the formation of micro-cracks. The growth of micro-cracks in the shearing area is an important factor in the generation of chips. By comparing the simulation results with the experimental results, the modified constitutive model is closer to the experimental results, indicating that the established theoretical model based on the strain gradient can better reflect the cutting process of particle-reinforced metal matrix composites.

Statistical Analyses of the Strengths of Particulate Reinforced Metal Matrix Composites (PRMMCs) Subjected to Multiple Tensile and Shear Stresses

For design and application of particulate reinforced metal matrix composites (PRMMCs), it is essential to predict the material strengths and understand how do they relate to constituents and microstructural features. To this end, a computational approach consists of the direct methods, homogenization, and statistical analyses is introduced in our previous studies. Since failure of PRMMC materials are often caused by time-varied combinations of tensile and shear stresses, the established approach is extended in the present work to take into account of these situations. In this paper, ultimate strengths and endurance limits of an exemplary PRMMC material, WC-Co, are predicted under three independently varied tensile and shear stresses. In order to cover the entire load space with least amount of weight factors, a new method for generating optimally distributed weight factors in an n dimensional space is formulated. Employing weight factors determined by this algorithm, direct method calculations were performed on many statistically equivalent representative volume elements (SERVE) samples. Through analyzing statistical characteristics associated with results the study suggests a simplified approach to estimate the material strength under superposed stresses without solving the difficult high dimensional shakedown problem.

Investigation on Stir Casting Fabrication Method Issues Analysis of Aluminium Metal Matrix Composites

Among the various types of manufacturing process methods for discontinuous metal matrix composite, stir casting is the best suitable manufacturing process to fabricate particulate reinforced metal matrix composite. Its benefit is its simplicity, durability, and adaptability. The main issue in this process is proper wetting of reinforcement in aluminium matrix material. Only proper wetting results in a homogeneous dispersion of reinforcement material, and these homogeneous dispersions help to improve the properties of metal matrix composite material. The purpose of this paper was to discuss the outline of the stir casting process, process parameters, and the contribution effect of process parameters. This paper also presents about of the conditions should follow during the addition of reinforcement material and matrix material pouring in mould cavity. This paper also discusses the conditions that must be met during the addition of reinforcement material and matrix material pouring in the mould cavity. This paper also looked into the impact and contribution of stirring casting time, speed, and temperature in aluminium metal matrix composites, as well as processing issues in aluminium metal matrix composites, challenges, and research opportunities.

Research on chip formation mechanism and surface morphology of particle-reinforced metal matrix composites

In this paper, a finite element (FE) cutting model for particle-reinforced metal matrix composites (PRMMCs) considering material damage was developed to predict SiC particle failure, cutting forces, and machined surface topography in SiCp/Al composite machining, and to analyze the dynamic mechanisms of chip formation and particle failure evolution. The validity of the simulation model was verified by comparing the simulation results with the cutting forces and surface topography obtained from the milling machining experiments. It was found that complex stress-strain fields exist in SiCp/Al composites with mesoscopic non-homogeneous structures, and alternating reticulation of tensile and compressive stress between particles was observed; particle failure due to tool-workpiece interaction exists in both direct and indirect ways; particle failure and local chip deformation during machining affect surface topography and chip shaping, resulting in serrated chips, pitting on the machined surface, and residual particle fragments.

Evolution of Residual Stresses and Fracture in Thermomechanically Loaded Particle-Reinforced Metal Matrix Composites

Evolution of Residual Stresses and Fracture in Thermomechanically Loaded Particle-Reinforced Metal Matrix Composites

Mechanical and Tribological Properties of Co-Electrodeposited Particulate-Reinforced Metal Matrix Composites: A Critical Review with Interfacial Aspects.

Particulate-reinforced metal matrix composites (PRMMCs) with excellent tribo-mechanical properties are important engineering materials and have attracted constant scientific interest over the years. Among the various fabrication methods used, co-electrodeposition (CED) is valued due to its efficiency, accuracy, and affordability. However, the way this easy-to-perform process is carried out is inconsistent, with researchers using different methods for volume fraction measurement and tribo-mechanical testing, as well as failing to carry out proper interface characterization. The main contribution of this work lies in its determination of the gaps in the tribo-mechanical research of CED PRMMCs. For mechanical properties, hardness is described with respect to measurement methods, models, and experiments concerning CED PRMMCs. The tribology of such composites is described, taking into account the reinforcement volume fraction, size, and composite fabrication route (direct/pulsed current). Interfacial aspects are discussed using experimental direct strength measurements. Each part includes a critical overview, and future prospects are anticipated. This review paper provides an overview of the tribo-mechanical parameters of Ni-based co-electrodeposited particulate-reinforced metal matrix composite coatings with an interfacial viewpoint and a focus on hardness, wear, and friction behavior.

A study on tribological behaviour and analysis of ZnO reinforced AA6061 matrix composites fabricated by stir casting route

PurposeThe most promising replacements for the industrial applications are particle reinforced metal matrix composites because of their good and combined mechanical properties. Currently, the need of matrix materials for industrial applications is widely satisfied by aluminium alloys. The purpose of this paper is to evaluate the tribological behaviour of the zinc oxide (ZnO) particles reinforced AA6061 composites prepared by stir casting route.Design/methodology/approachIn this study, AA6061 aluminium alloy matrix reinforced with varying weight percentages (3%, 4.5% and 6%) of ZnO particles, including monolithic AA6061 alloy samples, is cast by the most economical fabrication method, called stir casting. The prepared sample was subjected to X-ray photoelectron spectroscopy (XPS) analysis, experimental density measurement by Archimedian principle and theoretical density by rule of mixture and hardness test to investigate mechanical property. The dry sliding wear behaviour of the composites was investigated using pin-on-disc tribometer with various applied loads of 15 and 20 N, with constant sliding velocity and distance. The wear rate, coefficient of friction (COF) and worn surfaces of the composite specimens and their effects were also investigated in this work.FindingsXPS results confirm the homogeneous distribution of ZnO microparticles in the Al matrix. The Vickers hardness result reveals that higher ZnO reinforced (6%) sample have 34.4% higher values of HV than the monolithic aluminium sample. The sliding wear tests similarly show that increasing the weight percentage of ZnO particles leads to a reduced wear rate and COF of 30.01% and 26.32% lower than unreinforced alloy for 15 N and 36.35% and 25% for 20 N applied load. From the worn surface morphological studies, it was evidently noticed that ZnO particles dispersed throughout the matrix and it had strong bonding between the reinforcement and the matrix, which significantly reduced the plastic deformation of the surfaces.Originality/valueThe uniqueness of this work is to use the reinforcement of ZnO particles with AA6061 matrix and preparing by stir casting route and to study and analyse the physical, hardness and tribological behaviour of the composite materials.

Comparison of the effects of Mg and Zn on the interface mismatch and compression properties of 50 vol% TiB2/Al composites

Low ductility limits the extensive application of high volume fraction (>30 vol%) ceramic particle-reinforced metal matrix composites, and the simultaneous improvement of strength and ductility is still a challenge owing to the smaller amount of matrix contained in such composites. In this paper, the effects of various contents of Mg or Zn (0, 6, 10 and 14 wt%) on the interface mismatch and compression properties of 50 vol% TiB2/Al composite fabricated in situ are comparatively studied. The results indicate that Mg has a better refinement effect than Zn on the TiB2 ceramic particles. Mg can reduce the crystallographic mismatch degree of the Al/TiB2 interface. 6 wt% Mg simultaneously increases the σ0.2, σUCS and εf of the composite into 780 MPa, 1162 MPa and 10.68%, compared with the composite without the addition of Mg, increasing 8.5%, 2.8% and 30.6%, respectively. However, the addition of Zn leads to serious distortion of the Al lattice and deteriorates the interface matching degree of Al/TiB2, so the addition of Zn generally improves the σ0.2 and σUCS while sacrifices the plasticity simultaneously. Furthermore, the contributions of various strengthening mechanisms of the matrix in the high volume fraction TiB2/Al composites are analyzed through a comparative study.

Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction.

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

Constitutive model of metal matrix composites at high strain rates and its application

Particle reinforced metal matrix composites (PRMMCs) frequently undergo impact or shock loading during routine utilization. However, studies on the dynamic response of PRMMCs are currently insufficient compared with those on the quasistatic response. In this study, the multi-particle representative volume element (RVE) models were established to comprehensively investigate the influence of particle parameters (particle content and aspect ratio) on the dynamic behavior of PRMMCs, and a modified dynamic constitutive law was proposed to describe the dynamic mechanical behavior of PRMMCs more efficiently based on the concept of particle breakage probability. The verification results show that the dynamic stress–strain behaviors predicted by the RVE models agree better with the experimental data than those predicted by single-particle unit cell (RUC) models. Furthermore, the results predicted by the modified dynamic constitutive law agree well with the corresponding experimental data because the effect of particle breakage was included in the modified dynamic constitutive law. This paper provides the necessary guidance for the development and preparation of the particle reinforced metal matrix composites.

Simulation of Tensile Deformation Behavior of PM-SiCp/2014Al Composite Based on RVE

Metal matrix composite (MMC) emerges at the right moment and is widely used in aviation, aerospace and other fields due to its intrinsic properties. Usually compression tests are used to study the mechanical properties and deformation behavior of MMC. However, it is very important to study the deformation damage and fracture behavior of MMC under tensile stress state. At present, the design basis for MMC tensile stress state test still need further study. To this end, this paper uses the representative volume element (RVE) model, to simulate and analyze the tensile deformation behavior of particle-reinforced metal matrix composites (PRMMCS) for PM-SiCp/2014Al as the typical materials, and the deformation damage and fracture are analyzed and discussed.

A fast numerical method of introducing the strengthening effect of residual stress and strain to tensile behavior of metal matrix composites

Thermal residual stress and strain (TRSS) in particle reinforced metal matrix composites (PRMMCs) are believed to cause strengthening effects, according to previous studies. Here, the representative volume element (RVE) based computational homogenization technique was used to study the tensile deformation of PRMMCs with different particle aspect ratios (AR). The influence of TRSS was assessed quantitatively via comparing simulations with or without the cooling process. It was found that the strengthening effect of TRSS was affected by the particle AR. With the average strengthening effect of TRSS, a fast method of introducing the strengthening effect of TRSS to the tensile behavior of PRMMCs was developed. The new method has reduced the computational cost by a factor 2. The effect of TRSS on continuous fiber-reinforced metal matrix composite was found to have a softening-effect during the entire tensile deformation process because of the pre-yield effect caused by the cooling process.

Strengthening and Weakening Effects of Particles on Strength and Ductility of SiC Particle Reinforced Al-Cu-Mg Alloys Matrix Composites.

The strengthening and weakening effects of SiC particles on composite strength and ductility were studied. Al-Cu-Mg alloys matrices with three different mechanical properties were used. Their yield strength, ultimate strength, and elongation range from 90 to 379 MPa, 131 to 561 MPa, and 18% to 31%, respectively. SiC particles with sizes of 4, 8, 12, 15, 20, and 30 μm were used to reinforce these three matrices, separately, and the composites of eighteen combinations of the particle sizes and matrix strengths were manufactured. Yield strength, ultimate strength, elongation, and fracture morphology of these composites were characterized. Based on the analysis, the strengthening to weakening behavior on strength and ductility were comprehensively discussed. The critical particle size having the best ductility was obtained. The strengthening limit and match range of the particle and the matrix to achieve effective strengthening were defined as a function of the particle size and matrix strength. This work offers an important reference for optimization of mechanical properties of the particle-reinforced metal matrix composites.

Effect of Cryogenic treatment on Wear Properties of Aluminum Al356 – Zirconium Silicate Particulate Metal Matrix Composite

Metal matrix composite (MMC’s) are very much familiar in the field like automobile and aerospace industries owing to their excellent wear and mechanical properties . The fundamental aim of this paper is to augment cognizance amongst the researchers and to attract their consideration towards the present approach to treat with the cryogenic usage for the nonferrous metals. In this writing it is endeavor to deliver the examination findings of character of cryogenic usage on Wear Properties of Al356-ZrSiO4 Particulate Reinforced metal matrix Composites adapted by Stir Casting technique. The amount of reinforcement is changed from 0 to 12wt% in track of 3 %. The ready composites are exposed to wear testing as per ASTM standards using pin on disc machine .The hardness of the composites was found to augment with augment in reinforcement in the composite. The inference obtained discloses that as reinforcement content in the composites increment and execution of cryogenic usage to composite amended the wear resistance.

Role of homogeneous distribution of SiC reinforcement on the characteristics of stir casted Al–SiC composites

Stir casting process is very popular for the fabrication of particle reinforced metal matrix composites. However, achieving a homogenous distribution of the reinforcement particles is very challenging, which directly affect the final mechanical performances. In this research, a detailed investigation was conducted to obtain a superior synthesis of Al–SiC composite materials and to detect the effect of SiC particles distribution on the mechanical characteristic of the stir casted Al matrix composites using glycerol–water based model. The glycerol–water based model study displays the impacts of viscosity of Al melt (1.04–1.24 mPa.s), impeller position (10–50%), stirring speed (100–300 rpm) and blade angle (0–90°) on the vortex height, dispersion time, settling time and clustering of particles. The results of the experiments using glycerol–water based model, 45° blade angles, impeller position of 40% from the base, stirring speed of 250 rpm showed the best uniform distribution of reinforcement particles. Confirmation experiments were carried out by fabricating Al–SiC PRMMC based on three different viscosities (1.04, 1.13, and 1.24 mPa.s) of Al melt and considering other parameters as constant. Fabricated Al–SiC samples were analysed by Scanning Electron Microscope (SEM) and mechanical testing such as tensile, hardness and wear tests. Based on the confirmation results, the viscosity of 1.13 mPa.s for Al melt (at 750 °C) resulted in uniform distribution of SiC particles, which enhanced the tensile strength by 4%, wear resistance by 21%, and led to a uniform hardness value of 47 VHN throughout the composites.

A rate-dependent peridynamic model for predicting the dynamic response of particle reinforced metal matrix composites

To predict the mechanical properties and reproduce the dynamic fracturing behaviors of the particle reinforced metal matrix composites, the mesh-free composite models are constructed using peridynamic (PD) theory. On this basis, a rate-dependent PD model is proposed and introduced into the bond-based PD formulation. In this model, the classic Johnson-Cook (JC) equation is modified to characterize the non-linear strain rate effect on the performance of the matrix. The good agreement between the predicted results and the experimental results validates the applicability of the constitutive model. Then we take the thermal mismatch strengthening mechanisms into account for better describing the strong obstacles to the dislocation movement in composite brought by the stacking inclusions. After that, the obtained constitutive model is applied in PD simulations. The unit-particle model is discussed firstly to reveal the damage and failure mechanisms of the composite during the failure process under different strain rate loadings. The results present that the strain rate will change the failure mode and consequently influence the mechanical properties including the ductility and the strength in given strains. Furthermore, the multi-particle models are taken into account, a non-negligible factor, i.e., particle volume fraction, is introduced for systematic study.

Study on predicting the mechanical properties and fracturing behaviors of particle reinforced metal matrix composites by non-local approach

Peridynamic is applied to construct the mesh-free composite models for predicting mechanical responses of the particle reinforced metal matrix composites in this work. The effects of varying particle shapes and the interface properties on the mechanical properties and fracturing behaviors of the composite are considered individually. In addition to the numerical results (stress–strain relations), various distributed nephograms such as stress state and damage during the simulations are captured for analyzing detailedly. The results show that the particle shape strongly influences the concentrated stress state, eventually affecting the fracturing properties. Furthermore, the dominant failure mode may change by modifying the particle angle, two fracture ways can be observed correspondingly. Besides, the failure mode can also be controlled by regulating the interface strength. When the interface getting enhanced, the failure mode will transform from the interface debonding into the ductile fracture of the metal matrix gradually.

Effect of the Particle Size and Matrix Strength on Strengthening and Damage Process of the Particle Reinforced Metal Matrix Composites.

Roles of the particle, strengthening, and weakening during deformation of the particle reinforced metal matrix composite, were studied using in situ technique. Composites with three different strengths Al-Cu-Mg alloy matrices reinforced by three sizes SiC particles were manufactured and subjected to in situ tensile testing. Based on in situ observation, damage process, fraction and size distribution of the cracked particles were collected to investigate the behavior of the particle during composite deformation. The presence of the particle strengthens the composite, while the particle cracking under high load weakens the composite. This strengthening to weakening transformation is controlled by the damage process of the particle and decided by the particle strength, size distribution, and the matrix flow behavior together. With a proper match of the particle and matrix, an effective strengthening can be obtained. Finally, the effective match range of the particle and the matrix was defined as a function of the particle size and the matrix strength.