Particle Reinforced Metal Matrix Composites Research Articles

Crystal Chemistry at Interfaces Between Liquid Al and Polar SiC{0001} Substrates

Silicon carbide (SiC) has been widely added into light metals, e.g., Al, to enhance their mechanical performance and corrosion resistance. SiC particle-reinforced metal matrix composites (SiC-MMCs) exhibit low weight/volume ratios, high strength/hardness, high corrosion resistance, and thermal stability. They have potential applications in aerospace, automobiles, and other specialized equipment. The macro-mechanical properties of Al/SiC composites depend on the local structures and chemical interactions at the Al/SiC interfaces at the atomic level. Moreover, the added SiC particles may act as potential nucleation sites during solidification. We investigate local atomic ordering and chemical interactions at the interfaces between liquid Al (Al(l) in short) and polar SiC substrates using ab initio molecular dynamics (AIMD) methods. The simulations reveal a rich variety of interfacial interactions. Charge transfer occurs from Al(l) to C-terminating atoms (Δq = 0.3e/Al on average), while chemical bonding between interfacial Si and Al(l) atoms is more covalent with a minor charge transfer of Δq = 0.04e/Al. The prenucleation at both interfaces is moderate with three to four recognizable layers. The information obtained here helps increase understanding of the interfacial interactions at Al/SiC at the atomic level and the related macro-mechanical properties, which is helpful in designing novel SiC-MMC materials with desirable properties and optimizing related manufacturing and machining processes.

Quantifying laser irradiation-induced temperature field of particle reinforced metal matrix composites

While particle-reinforced metal matrix composites (PMMCs) are composed of particles and matrix with distinctly different thermomechanical properties, the thermal differences and coupled interactions between individual phases greatly determine the thermal characteristics of PMMCs under laser irradiation. In this work, we quantify the temperature evolution characteristics within SiCp/Al under laser irradiation by microstructural thermal finite element simulations and experimental investigation. Specifically, a 2D thermophysical FE model of laser-SiCp/Al interaction for the two-phase PMMCs material under laser irradiation is developed, which incorporates the temperature-dependent thermophysical properties of particles, matrix and interfaces, along with the considerations of the shape and distribution characteristics of particles, as well as the comprehensive thermal conditions. Furthermore, a 3D equivalent thermal FE model for experimental validation of predicted laser-induced temperature of SiCp/Al is developed, based on the derived equivalent properties. Meanwhile, an in-situ temperature measurement system is constructed for exploring temperature evolution characteristics during the on-going laser irradiation process, which validates a derivation of 1.7 % of predicted temperature by the equivalent thermal FE model. Finally, the impact of laser processing parameters on the temperature field of SiCp/Al is addressed. These findings provide valuable insights for understanding the thermal mechanisms of PMMCs under laser irradiation, and also the parameter optimization for laser processing of PMMCs.

Finite element analysis and experimental study on the cutting mechanism of SiCp/Al composite in laser ultrasonic elliptic vibration turning

SiCp/Al composites have excellent material properties and are increasingly being used in the aerospace, military, and electronic packaging industries. However, the inhomogeneity and non-conductivity of conventional turning (CT) results in poor material surface quality and high cutting forces, which seriously hinder the application of particlereinforced metal matrix composites. The thermal softening property of laser-assisted turning (LAT) and the intermittent cutting property of two-dimensional (2D) ultrasonic elliptical vibratory turning (UEVT) offer unique advantages in improving material surface quality. Therefore, a novel laser ultrasonic elliptical vibratory turning (LUEVT) machining technique is proposed to improve the machining of SiCp/Al composites with two different volume fractions. The effect of highfrequency intermittent machining on material processing was further investigated by adjusting the pulsed laser power. Finite element modelling was used to predict the machining state, surface roughness, and chip morphology between the workpiece and the PCD tool. The effects of varying the machining parameters during the experiment on the two composites were analysed. The results showed that the LUEVT of 25 % and 45 % SiCp/Al composites were reduced by 39.3 % and 30.7 % respectively compared to the CT cutting forces. The experiments verified the consistency of the surface roughness and chip morphology with the finite element simulation results. The stability of the cutting force during the cutting process is also improved, as the material removal process mainly takes the form of small particle fragmentation and matrix encapsulation.

Insights into particle dispersion and damage mechanisms in functionally graded metal matrix composites with random microstructure-based finite element model

This study investigates the impact of Al2O3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathrm {Al_2O_3}$$\\end{document} particle volume fraction and distribution on the deformation and damage of particle-reinforced metal matrix composites, particularly in the context of functionally graded metal matrix composites. In this study, a two-dimensional nonlinear random microstructure-based finite element modeling approach implemented in ABAQUS/Explicit with a Python-generated script to analyze the deformation and damage mechanisms in AA6061-T6/Al2O3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathrm{AA6061\\mbox{-}T6/Al_2O_{3}}$$\\end{document} composites. The plastic deformation and ductile cracking of the matrix are captured using the Gurson–Tvergaard–Needleman model, whereas particle fracture is modelled using the Johnson–Holmquist II model. Matrix-particle interface decohesion is simulated using the surface-based cohesive zone method. The findings reveal that functionally graded metal matrix composites exhibit higher hardness values (HRB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{HRB}$$\\end{document}) than traditional metal matrix composites. The results highlight the importance of functionally graded metal matrix composites. Functionally graded metal matrix composites with a Gaussian distribution and a particle volume fraction of 10% achieve HRB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{HRB}$$\\end{document} values comparable to particle-reinforced metal matrix composites with a particle volume fraction of 20%, with only a 2% difference in HRB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{HRB}$$\\end{document}. Thus, HRB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{HRB}$$\\end{document} can be improved significantly by employing a low particle volume fraction and incorporating a Gaussian distribution across the material thickness. Furthermore, functionally graded metal matrix composites with a Gaussian distribution exhibit higher HRB\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{HRB}$$\\end{document} values and better agreement with experimental distribution functions when compared to those with a power-law distribution.

A machine learning strategy for enhancing the strength and toughness in metal matrix composites

Particle-reinforced metal matrix composites (MMCs) are highly sought after for various applications due to their robust mechanical properties containing high strength and high elastic modulus. However, the introduction of highly rigid particles inevitably causes drastic degradation of toughness, resulting in the trade-off between strength and toughness in MMCs. This work proposed a multi-structure, multi-objective collaborative enhancement cyclic strategy that seamlessly integrates machine learning (ML) and genetic algorithms for realizing synergistic improvement of strength and toughness with the forward prediction and inverse exploration. By leveraging diverse configurations in MMCs such as laminate, network, and micro/nano hybrid structures, robust datasets were initially constructed. Random forest regression (RFR) was employed as surrogate model for forward prediction, accurately estimating the elastic modulus, yield strength, ultimate tensile strength, and toughness. Inverse exploration was also conducted using the combination of RFR and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to identify optimized structures with favorable strength-toughness matching. Utilizing this strategy, this work explores the microstructures with synergistic enhancement of strength and toughness, being confirmed by finite element analysis (FEA). The proposed optimization strategy, demonstrated in particle-reinforced MMCs, offers a promising solution to the trade-off between strength and toughness and is highly transferrable to other material systems.

Observing and Modeling the Wear Process of Heterogeneous Interface.

Understanding and controlling the wear process of heterogeneous interfaces between soft and hard phases is crucial for designing and fabricating materials, such as improving the wear resistance of particle reinforced metal matrix composites and the accuracy and efficiency of chemical mechanical polishing. However, the wear process can be hardly observed, as interfaces are buried under the surface. Here, we proposed a nanowear test method by combining focused ion beam cutting to expose interfaces, atomic force microscopy to rub against interfaces, and scanning electron microscope to characterize the interface damage. Using this method, three typical wear forms had been observed in Al/SiC composite, i.e., merely matrix wear, particle fracture, and particle pullout. A theoretical model was proposed that revealed that the increasing interfacial friction would induce particle fracture or pullout, depending on the particle edge angle and tip edge angle. This work sheds light on wear control in composites and nanofabrication.

Ultrafast fabrication of W/Cu composites using flash sintering

When the proportion of reinforcing phases is high and the wettability between the secondary phase and the metal is poor, preparing fully dense particle-reinforced metal matrix composites becomes challenging. This study employs the flash sintering method to prepare fully dense WCu20 composite materials within a few tens of seconds. It is found that during the “thermal runaway' process of flash sintering, the Cu phase undergoes rapid melting and solidification, and the core mechanism of material densification is that pressure causes Cu liquid to quickly fill the gaps between tungsten particles. Pressure not only promotes the contraction of the framework formed by tungsten particles but also facilitates the complete filling of gaps within the tungsten frameworks by the Cu liquid and promotes the rapid expulsion of bubbles from the Cu liquid, thereby achieving rapid densification of WCu20 composite materials. Moreover, an increase in the temperature enhances the fluidity of the Cu liquid, which aids in filling the gaps between tungsten particles and promotes the discharge of bubbles from the Cu liquid. Flash sintering is a common technique for the sintering and densification of metal powders, suitable for the rapid preparation of various metal matrix composites.

Ultra-high strength metal matrix composites (MMCs) with extended ductility manufactured by size-controlled powder and spherical cast tungsten carbide

The main challenge of particle reinforced metal matrix composites (MMCs) is balancing strength and ductility. This research uses type 420 stainless steel and spherical cast tungsten carbide (WC/W2C) with a similar powder size and range as raw powders to manufacture laser powder bed fusion (LPBF) 420 + 5 wt% WC/W2C MMCs. LPBF 420 + 5 wt% WC/W2C MMCs contain austenite, martensite, and W-rich carbides (WC/W2C, FeW3C, M6C, and M7C3) from nanometre to micrometre scale. The well-balanced composition creates a crack-free reaction layer between the reinforced particles and matrix. This reaction layer consists of two distinct layers, depending on the element concentration. The LPBF 420 + 5 wt% WC/W2C MMCs achieved an excellent compressive strength of ∼5.5 GPa and a considerable fracture strain exceeding 50 %. The underlying mechanisms for the improved mechanical properties are discussed, providing further insight to advance the application of MMCs via additive manufacturing.

Regulating the microstructure of Ti@TiAlSi core-shell structured reinforcing particles endows Al–Si alloy matrix composites with high strength and ductility

Forming spherical core-shell (CS) structured reinforcing particles, consisting of a Ti core and a surrounding TiAlSi intermetallic shell, by in situ reaction between Ti and Al matrix is a promising approach to overcome the strength-ductility trade-off in particle reinforced Al–Si matrix composites. However, the phase constituent and microstructure of the shells are highly sensitive to the Al–Si alloy composition and processing parameters of the powder thixoforming method. Therefore, the effects of Si content and partial remelting temperature on the microstructure of CS particles and the tensile properties of the resultant composites were investigated in this study. The results indicate that uniform and compact shell can be achieved only by the τ2-phase reaction layer generated during partial remelting. To form the τ2 phase, the Si content in the liquid phase of the semisolid billet prior to thixoforming must be higher than 10.3 wt%. This can be achieved through adjusting the Si content in the Al–Si alloy matrix or/and partial remelting temperature. Moreover, the Ti core radius to shell thickness ratio of ∼1.5 was proposed to achieve the composites with both high strength and ductility. These findings are helpful for designing the microstructure and fabricating CS particles reinforced metal matrix composites with excellent comprehensive mechanical properties.

Enhanced wear resistance of TiC/Ti6Al4V composites through changing TiC morphologies in laser direct energy deposition

The wear performance of particle-reinforced metal matrix composites is significantly influenced by the morphologies of ceramic particles. In this study, the friction and wear characterization of titanium matrix composites (TMCs) with different TiC morphologies was studied. This TMCs, consisting of 20 wt% of TiC, was prepared by laser direct energy deposition (LDED). Different LDED parameters are employed to changing the morphologies of TiC. Two distinct TiC morphologies, equiaxed and dendritic, are achieved by varying the laser scanning speed and laser power during the LDEDed TMCs. The friction and wear tests of TMCs with different TiC morphologies are carried out by using a ball-on flat reciprocating tribometer. The results reveal that TMCs with different TiC morphologies manifest divergent wear mechanisms. TMCs with equiaxed TiC dominates three-body wear due to the fracture debonding and pulling out of TiC, resulting in a higher wear rate. TMCs with dendritic TiC mainly dominates two-body wear, facilitated by the protection of hard dendrites and the tribolayer, which leads to a 59% improvement in wear resistance compared to TMCs with equiaxed TiC. This work provides a method of TiC morphologies changing to achieve an enhanced wear performance for TMCs.

Selective laser melting and mechanical behavior of Mo-coated diamond particle reinforced metal matrix composites

Defects, such as pores, microcracks, and thermal damage, pose significant challenges in the selective laser melting (SLM) process of diamond reinforced metal matrix composites. To address these issues, this study utilizes Mo-coated diamond particles prepared via salt bath plating for SLM processing of CoCr-diamond composites. The SLM process parameters including laser power, scanning speed, and hatch spacing were systematically optimized using the response surface method (RSM). Subsequently, the microstructure and mechanical properties of the SLMed CoCr-diamond composites were thoroughly investigated. Notably, a protective layer of Mo2C is formed on the surface of diamond particles during the salt bath plating process. When compared to the SLMed CoCr-15 vol% Mo-uncoated diamond composite, the Mo coating significantly enhances the compressive strength by 69 % and flexural strength by an impressive 345 % for the CoCr-15 vol% Mo-coated diamond composite.

Effect of Graphene Particle Diameter on Mechanical Properties of Graphene Composite Material

In order to improve the mechanical properties of alloys and broaden their application fields, high-performance metal matric composites have received more and more attention. Graphene has excellent mechanical properties and is often used as a reinforcing phase for various composite materials. However, as the reinforcing phase of the composite, the number, shape, and size of graphene have a significant effect on the overall mechanical properties of the composites. Therefore, the influence of graphene particle diameter on the mechanical properties of graphene particle reinforced metal matrix composites was studied in this paper. By establishing a series of finite element models, we simulated the mechanical behaviour of composite materials under static tension loading. The relationship between graphene particle diameter and material mechanical properties is revealed.

Advancing heat-tolerant composites with coherent ladder interfaces via constructing extremely fine nanolamellar solute-twining architectures

The interface of ceramic particles and metal matrixes extremely impacts the mechanical properties of particle-reinforced metal matrix composites, especially at elevated temperatures. We provide a strategy for constructing extremely fine, in situ-formed coherent nanolamellar solute-twining architectures in a supersaturated MAX/Ni composite to modify the interface, aiming for higher strengths. Through this unique architecture, a coherent interface of ceramic particles and a metal matrix is formed, with an enormous coherent interface known as a ladder interface. The tensile strength at 1023 K is approximately 1 GPa by forming a thermally stable Schwarz crystal structure (< 3 nm). Developing heat-tolerant composites using this architecture may enhance the materials’ available properties for high-temperature applications.

Optimization of wire spark erosion machining of Grade 9 titanium alloy (Grade 9) using a hybrid learning algorithm

Manufacturing has grown challenging because of the increased usage of harder materials, such as titanium alloys, in many industries, such as aerospace, automobiles, and marine. Conventional material removal procedures are not suitable for these tough materials due to their increased hardness and slow machinability. Wire Electrical discharge machining (WEDM) is a modern approach for material removal, particularly for harder materials, such as titanium alloys, nickel alloys, hard particle reinforced metal matrix composites, etc. The research design was performed by deeming the independent factors, such as duration of pulse and applied current. The removal rate of material, surface roughness of the machined region, dimensional deviation, and tolerance errors in form/orientation are considered performance metrics. Taguchi’s approach was engaged to assess the process variables, and the importance of the process factors was established using analysis of variance approach. The purpose of this research is to create an AI based decision making tool, which can be utilized to anticipate the various parameters that impact the WEDM material removal process. The discoveries of the present exploration allowing the manufacturers to make better-informed decisions with a developed model’s capability by demonstrating that the model’s predicted values were in close confirmation to the actual values.

Influence of surface integrity on the fatigue performance of TiB2/Al composite treated by ultrasonic deep rolling: Experiments and simulations

The influences of surface integrity on the fatigue performance of in-situ 6 wt% TiB2/2024Al composite treated by ultrasonic deep rolling (UDR) were comprehensively investigated with both experiments and simulations. Results reveal that only a single pass of UDR treatment can impressively reduce the surface roughness of the fine-turned specimens by 94 %. Moreover, axial compressive residual stress (RSc) larger than −400 MPa and strain hardening (SH) higher than 50 % were obtained on the surface. The comprehensive effect of these surface integrity improvements has enhanced the fatigue limit by 22 %, extended the fatigue life by 10∼20 times, and expanded the safe region in the Goodman-Haigh graph by 14.6 %. More importantly, UDR significantly dispersed the TiB2-particle aggregates in the composite surface, which provided the possibility of improving the surface comprehensive mechanical properties of particles reinforced metal matrix composites (PRMMCs) through a simple and convenient mechanical way.

Computational damage analysis of metal matrix composites to identify optimum particle characteristics in indentation process

This paper presents an integrated numerical model that investigates the effects of Al2O3 particle volume fraction, distribution, size, shape, and clustering on the deformation, damage, and failure behaviors of particle-reinforced metal matrix composites. Additionally, the effects of the cohesive strength of the matrix-particle interface and the initial void volume fraction on these behaviors are investigated. In this study, random microstructure-based finite element modeling approach is used. The Gurson-Tvergaard-Needleman model is used to capture the plastic deformation and ductile cracking of the matrix, whereas the Johnson–Holmquist II model is used to model particle fracture. The matrix-particle interface decohesion is modeled using the surface-based cohesive zone method. A two-dimensional nonlinear finite element model augmented with Python-generated code is developed in ABAQUS/Explicit to analyze the damage mechanisms in AA6061-T6/Al2O3 particle-reinforced metal matrix composites. The results show that Al2O3 particle enhance the ability of particle-reinforced metal matrix composites to resist deformation. However, this enhancement is dependent on the indentation location, particulate characteristics, and the applied load. An increase in the particle volume fraction increases the risk of particle fracture, particularly when particles are close to the material surface. Circular particles are the optimal choice for the reinforcement of particle-reinforced metal matrix composites. The predictions are in good agreement with the experimental data, particularly in terms of Rockwell hardness and deformation characteristics.

Enhanced machinability of aluminium-based silicon carbide by non-resonant vibration-assisted magnetorheological finishing

Aluminium-based silicon carbides (SiCp/Al) have been widely used due to their inherent unique physical and mechanical properties. However, improving the surface quality is challenging as finishing cannot meet the requirements of removing the height differences caused by the SiC and aluminium phases. This study aims to investigate the effectiveness of non-resonant vibration-assisted magnetorheological finishing (NVMRF) in reducing the referred height differences and then to enhance the surface quality. Finite element modeling (FEM) and molecular dynamics (MD) simulations were utilized to analyze the influence of the vibration on the fragmented particles as well as the reduction of two-phase height difference. Nano scratch experiments reveal the removal mechanism of the SiC phase in NVMRF. A material removal rate (MRR) model considering the influence of the exerted forces of abrasive particles and the concept of micro-removal mechanism was established. When analyzing the machining results, it was found that the plastic removal in the SiC phase contributed to the NVMRF. Besides, it was verified that the vibration-induced tangential force effectively reduced the height difference. Although there is a slight discrepancy between the theoretical and experimental values of the finishing force within the experimental parameters, the consistent trend confirms the effectiveness of the proposed method. Finally, this research provides a valuable method for finishing the particle-reinforced metal matrix composites (PRMMCs).

An Al–Mg layered double oxide architectured Al2O3/AZ91D composites in balancing the strength-ductility trade-off

The strength-ductility trade-off has long challenged particle-reinforced metal matrix composites (MMCs). This paper presents an Al–Mg layered double oxide (LDO consisted of Al2O3(1 2‾10)//MgAl2O4(004)//MgO(002) at the Al2O3 side, and a MgO(200)//Mg(1 1‾02) the Mg matrix side) architectured Al2O3/AZ91D composite. The intermediate LDO bonds the inner hard Al2O3 reinforcement and the soft AZ91D matrix, which is beneficial to the trade-off between strength and plasticity of ceramic particle reinforced MMCs. An effective load-transfer enhancement and easy dislocation-bypass across the LDO with a set of coherent pairs (Al2O3–MgAl2O4, MgAl2O4–MgO, MgO–Mg, contributes to this synchronization improvement of strength and plasticity. This work sheds some light on fabricating Mg matrix composites with high strength and ductility.

Strategies and Outlook on Metal Matrix Composites Produced Using Laser Powder Bed Fusion: A Review

Particle-reinforced metal matrix composites (MMCs) produced using the laser powder bed fusion (LPBF) technique have gained considerable attention because of their distinct attributes and properties in comparison with conventional manufacturing methods. Nevertheless, significant challenges persist with LPBF-fabricated MMCs: more design parameters over commercially available alloys and several defects resulting from inappropriate process conditions. These challenges arise from the intricate interaction of material- and process-related phenomena, requiring a fundamental understanding of the LPBF process to elucidate the microstructural evolution and underlying mechanisms of strengthening. This paper provides a comprehensive overview of these intricate phenomena and mechanisms, aiming to mitigate the process-related defects and facilitate the design of MMCs with enhanced mechanical properties. The material processing approach was suggested, covering from material design and LPBF to postprocessing. Furthermore, the role of in situ heat treatment on the microstructure evolution of MMCs was clarified, and several novel, potential strengthening theories were discussed for the LPBF-fabricated MMCs. The suggested strategies to address the challenges and design high-performance MMCs will offer an opportunity to develop promising LPBF-fabricated MMCs, while overcoming the material limitations of LPBF.

The Effect of Processing Techniques and Operating Parameters on the Erosion Wear Behavior of Particle-Reinforced Metal Matrix and Surface Composites: A Review

The Effect of Processing Techniques and Operating Parameters on the Erosion Wear Behavior of Particle-Reinforced Metal Matrix and Surface Composites: A Review