Particle Reinforced Aluminum Matrix Composites Research Articles

Tribological behavior of high-entropy alloy particle reinforced aluminum matrix composites and their key impacting factors

Al0.5CoCrFeNi high-entropy alloy particles reinforced aluminum matrix composites (HEAps/AMCs) with various reinforcement additions (0.5, 1.5, 3.0, and 5.0 wt%) were fabricated. The coefficient of friction (COF, about 0.45–0.47) and wear rate (0.32–0.40 10–3 mm3/Nm under 30 N) of HEAps/AMCs tribosystems with a moderate range of reinforcement (0.5–3.0 wt%) were lower than the matrix alloy. HEAps hindered plastic deformation of the contact surface, increasing the wear resistance of the AMCs. Due to the tight interface and the interaction between the HEA particles and dislocations, the AMC was stabilized during the wear tests and showed a dramatically improved capacity to resist crack initiation, propagation, and fracture around the interface.

Experiment and simulation of SiC particle-reinforced aluminum matrix composites fabricated by friction stir processing

The influence of the pre-implanted reinforced particles on the temperature field and the flow field of the processed zone directly determines the microstructure and properties of the aluminum matrix composites fabricated by friction stir processing (FSP). However, the differences in the characteristics of processed materials, especially the effect of pre-implanted reinforced particles on the flow of plastic materials, have rarely been reported. In this study, the temperature distribution of the processed zone was obtained by experimental measurement and numerical simulation. The model of the effect of the SiC particles as reinforced particles on the temperature field and the flow field of the processed zone was established. The influence of the SiC particles on the flow of plastic materials during the FSP was further investigated. The refinement, particle size, and distribution of the SiC particles in the processed zone of the FSPed multi-pass composites were also discussed in detail. The microhardness of the processed zone was also tested and discussed. The results showed that the temperature field at the contact interface between the SiC particles and the matrix in the processed zone was not continuously distributed. Due to the collision and hindrance of the reinforced SiC particles, the flow direction of plastic materials in the processed zone had been changed many times during the flow process. The initial average particle sizes of the SiC particles have a significant effect on the flow path of the processed plastic material. The microhardness of the processed zone of the FSPed specimens is significantly higher than that of the matrix.

Friction Stir Processing of Cold-Sprayed High-Entropy Alloy Particles Reinforced Aluminum Matrix Composites: Corrosion and Wear Properties

Friction Stir Processing of Cold-Sprayed High-Entropy Alloy Particles Reinforced Aluminum Matrix Composites: Corrosion and Wear Properties

Influence of machine variables on the microstructure and mechanical properties of AA6061/TiO2 friction stir welds

ABSTRACT The present work explicates the joining of TiO2 (rutile) particles reinforced aluminium matrix composites (AMCs) through the friction stir welding (FSW) technique. Joining of AMCs using conventional fusion welding techniques faces a lot of challenges, which can be overcome by the FSW process. The effect of the two most critical process variables, welding speed, and tool rotational speed on the grain structure of the joint and on the mechanical behaviours was evaluated. The study revealed that machine variables regulate the quantity of heat input, heat exposure duration, and rate of cooling, thereby, significantly altering the grain size in the weld region and mechanical behaviour of the joint. The tool rotational speed had a substantial impact on the joint strength, whereas tool traverse speed facilitates homogeneous dispersion of reinforced particles in the matrix. The ‘W’-shaped hardness variation profile was observed across the weld zone, showing the highest hardness in the weld stir zone. The UTS of the welded specimen, measured across the joint was almost equal to the parent material with fracture occurring at the interface of the heat-affected and the thermo-mechanically affected zone which was the weakest point in the weld region.

Surface Investigation of Physella Acuta Snail Shell Particle Reinforced Aluminium Matrix Composites

Aluminium-matrix composite is one of the most preferred engineering materials and is known for its potential benefits, such as lightweight nature, high specific stiffness, superior strength, machinability, etc. The metal–matrix composites are very attractive for critical applications: Aerospace field, defense deployments, automotive sector, marine industry. In the present work, novel Physella Acuta Snail Shell particle reinforced aluminium metal–matrix composites are developed to facilitate cost-effective and sustainable manufacturing. These green composites are developed by stir-casting with LM0 as matrix material and snail shell as reinforcement with a distinct percentage (by weight) of inclusion. The influence of snail shells is analyzed through tribological, morphological, and corrosion studies. Aluminium–matrix composite Al98SNS2 with 98% (by weight) aluminium matrix and 2% (by weight) snail shell reinforcement exhibits superior performance in all investigations. Al98SNS2 composite exhibits the least wear rate in the atmosphere of deionized water and 3.5% NaCl. Corrosion deteriorates the surface roughness irrespective of the percentage of incorporation of snail shell reinforcement. However, the deterioration is minimal in Al98SNS2. The current research findings indicate that the incorporation of snail shell in aluminum metal–matrix composites promotes cost-effective, sustainable, and eco-friendly manufacturing.

Modification of cold-sprayed high-entropy alloy particles reinforced aluminum matrix composites via friction stir processing

In this study, a kind of novel Al matrix composite reinforced by CoCrFeNi HEA particles was fabricated by cold spray (CS) and subsequent friction stir processing (FSP) for the first time. The microstructure and mechanical properties of cold-sprayed (CSed) and friction stir processed (FSPed) CoCrFeNip/6061Al composites were examined using scanning electron microscopy, energy dispersive spectroscopy, electron backscattering diffraction, X-ray diffraction, and hardness and tensile tests. The results demonstrated that CSed samples exhibited a number of micro-pores in the Al matrix with homogeneous distribution of HEA particles, but heterogeneously distributed grain size. Continuous dynamic recrystallization and geometric dynamic recrystallization occurred at the interface between the HEA particles and Al matrix. Following FSP, the micro-pores were eliminated, and a small amount of HEA particles was fragmented and uniformly dispersed in the Al matrix. Moreover, the average size of HEA particles was refined from ~21–14 µm. The Al matrix exhibited dynamic recrystallization and particle-stimulated nucleation recrystallization, thus resulting in an average grain size of ~1.9 µm. Obvious diffusion layers of 0.5 µm and 1 µm in thickness occurred at the interface between the HEA particles and Al matrix in CSed and FSPed samples, respectively. A new phase with a body-centered cubic structure was confirmed to be an HEA in diffusion layers. Compared with CSed samples, the microhardness, ultimate tensile strength, and elongation of the FSPed samples increased by 91%, 60%, and 130%, respectively. The improved mechanical properties are attributed to the high density and enhanced interfacial bonding. Thus, this study provided a novel method for preparing high-performance Al matrix composites reinforced by HEA particles.

Droplet impact-induced molten pool dynamics and particle migration patterns during TIG-assisted droplet deposition manufacturing of SiC particle-reinforced Al–Si alloy

A three-dimensional droplet-pool coupled model with dispersed phase was developed to simulate the TIG-assisted droplet deposition manufacturing (DDM) of silicon carbide (SiC) particle-reinforced aluminum (Al) matrix composites (AMCs), which was employed to calculate the surface morphology of the deposited layer, the thermal-flow fields and the distribution state of reinforcing particles in the molten pool. The cross-section profile of a single-track SiC-reinforced AMC deposit and the distribution state of reinforcements were examined and compared with the findings predicted by simulation, a good agreement was achieved. It is found that the falling Al droplet produces an obvious crater on the curved surface of molten pool. The viscous damping and simultaneous solidification are the main factors that dissipate the kinetic energy of the droplet. In addition, we discuss quantitatively how impact-induced thermodynamic within molten pool can change the migration behaviors and the distribution state of SiC reinforcement. The heterogeneous distribution of reinforcement particles can be attributed to the thermocapillary micro-convection and the velocity difference in the spreading and recoiling stages.

Investigation on tool wear in friction stir welding of SiCp/Al composites

The hard particles in particle-reinforced aluminum matrix composites significantly increases tool wear during friction stir welding (FSW), resulting in the shortage of tool life. In this study, SiCp/Al composites are used as the research object, and the tool wear experiment in friction stir welding is carried out by using high-speed steel pin and high-speed steel + AlCrN coated pin. A new method for calculating tool wear based on hydrodynamic pressure is proposed, and the tool pin wear prediction model is established and verified by experiments. The results show that the wear rate of AlCrN coated pin is very low at the beginning, indicating that AlCrN coating can extend the tool life to a certain extent. However, the wear rate of the tool will increase significantly after the coating is worn away. Through the analysis of the surface wear morphology of the pin, it is found that the main mechanisms of tool wear in the friction stir welding of SiCp/Al composites are the micro ploughing and micro cutting of SiC particles.

Ultrasound-assisted dispersion of TiB2 nanoparticles in 7075 matrix hybrid composites

Refinement and dispersion of rigid ceramic particles enhance the mechanical properties of particulate reinforced aluminum matrix composites (PRAMCs). However, nanoparticles are intrinsically clustered or agglomerated together in melts and thereby reduce their strengthening efficacy. Ultrasound cavitation and acoustic streaming can effectively improve the distribution of nanoparticles in melts. In this work, we use synchrotron radiation X-ray computed tomography (SR-CT) to unveil the particle dispersion mechanism by ultrasound vibration treatment (UVT) from three-dimensional perspective. The SR-CT results indicated that the mesoscale agglomerates in a high-strength 7075 aluminum alloys can be eliminated completely upon UVT. Two types of TiB2 particles have been identified, termed as micro-size TiB2 particles (MTPs) and nano-size TiB2 particles (NTPs), which were observed to be aggregated along the grain boundaries and dispersed uniformly within the α-Al grains, respectively. Tensile tests reveal significant strengthening of the composites in the as-cast state, suggesting effective Orowan strengthening. This strength enhancement is attributed to the dispersed NTPs that have been retained after solidification. It is also inspiring to see the concurrent increase in the ductility of the composites after UVT, thanks to the improvement in particle distribution.

Effects of Strength and Distribution of SiC on the Mechanical Properties of SiCp/Al Composites.

In this paper, considering the strength and geometric discrete distribution characteristics of composite reinforcement, by introducing the discrete distribution function of reinforcement, the secondary development of ABAQUS is realized by using the Python language, the parametric automatic generation method of representative volume elements of particle-reinforced composites is established, and the tensile properties of silicon carbide particle-reinforced aluminum matrix composites are analyzed. The effects of particle strength, particle volume fraction, and particle random distribution on the mechanical properties of SiCp/Al composites are studied. The results show that the random distribution of particles and the change in particle strength have no obvious influence on the stress–strain relationship before the beginning of material damage, but have a great influence on the damage stage, maximum strength, and corresponding failure strain. With the increase in particle volume fraction, the damage intensity of the model increases, and the random distribution of particles has a great influence on the model with a large particle volume fraction. The results can provide a reference for the design, preparation, and characterization of particle-reinforced metal matrix composites.

Mechanical property analysis of glass particulates reinforced Aluminum matrix composites

Technological advances involve materials with unique qualities that cannot be provided by ordinary metal alloys, ceramics, or polymeric materials. In the present work, an attempt is made to prepare glass particulates reinforced Aluminum Matrix Composites (AMCs). The composite was prepared using a stir casting process with 0 to 12 wt% glass particulates reinforcement with a particle size of 75 µm. The ASTM standard was used to test mechanical properties such as hardness and tensile strength. The results revealed that the Vickers hardness improved with an increase in weight fractions of glass particulates. The tensile strength increases up to 8 wt% of reinforcement, then decreases up to 12 wt% of reinforcement. The porosity level depicted an increasing trend as the volume percentage of reinforcement increase. The microstructure observation implies that the glass particulates were fairly distributed in 8 wt% and 12 wt% while reinforcement particles' clustering was observed in 4 wt% reinforced composites.

Configuration Effect and Mechanical Behavior of Particle Reinforced Aluminum Matrix Composites

Configuration Effect and Mechanical Behavior of Particle Reinforced Aluminum Matrix Composites

Investigation of mechanical characteristics of SiC and flyash particle reinforced aluminium matrix composites

Achieving a good balance of toughness, strength, stiffness, and density was difficult in the past. Metal matrix composites (MMCs) provide better specific strength, modulus, wear resistance, and damping capacity than non-reinforced composites and alloys. Fly ash is a cheap, low-density byproduct of the combustion process in thermal power plants. Composites reinforced with fly ash are expected to become more affordable in applications demanding low structural weight. A liquid Al containing ceramic particles is necessary for a good Al matrix cast composite, and Si is added to promote wettability. This thesis focuses on the efficient utilisation of fly ash, where particles ranging in size from 0.1 to 100 m were stir cast into an aluminium silicon matrix. The behaviour of these cast composites was studied using a scanning electron microscope and a range of mechanical tests. The composite was also subjected to a dry sliding wear test at varied loadsand velocities.

In-situ formation of particle reinforced Aluminium matrix composites by laser powder bed fusion of Fe2O3/AlSi12 powder mixture using laser melting/remelting strategy

In-situ preparation of particle reinforced Al matrix composites (PRAMCs) by laser powder bed fusion (LPBF) is a promising strategy to strengthen Al-based alloys. The laser-driven thermite reaction can be a practical mechanism to in-situ synthesise PRAMCs. However, the introduction of elements oxygen by adding Fe2O3 makes the powder mixture highly sensitive to form porosity and Al2O3 film during LPBF, bringing challenges to prepare dense materials. This work develops an LPBF processing strategy combined with consecutive high-energy laser melting scanning and low-energy laser remelting scanning to prepare dense PRAMCs from Fe2O3/AlSi12 powder mixture. A high relative density (98.2 ± 0.55 %) was successfully obtained by optimising laser melting (Emelting) and remelting energy density (Eremelting) to Emelting = 35 J/mm2 and Eremelting = 5 J/mm2. Results reveal the necessity to increase Emelting to improve metal liquid’s spreading/wetting by breaking up Al2O3 films surrounding molten pools; however, the high-energy laser melting produced much porosity. Low-energy laser remelting could close the resulting internal pores, backfill open gaps and smoothen solidified surfaces. Although with two-times laser scanning, the microstructure still shows fine cellular Si networks with Al grains inside (grain size 370 nm) and in-situ nano-precipitates (Al2O3, Si and Al-Fe(-Si) intermetallics). Finally, the fine microstructure, nano-structured dispersion strengthening and high-level densification strengthen the prepared in-situ PRAMCs, reaching yield strength of 426 ± 4 MPa and tensile strength of 473 ± 6 MPa. Furthermore, the results can provide valuable information to process other powder mixtures with severe porosity/oxide-film formation potential considering the evidenced contribution of laser melting/remelting strategy to densify material and obtain good mechanical properties during LPBF.

Mechanical behaviour of nano ceramic particles reinforced aluminium matrix composites

New propulsion materials are becoming increasingly popular as a result of the significant growth in industrial innovation over the last few years. Using nano-sized reinforcement materials in aluminium metal matrix composites, engineers will be able to satisfy new engineering demands. In the automobile and aircraft industries, as well as in general industry, they're widely employed. A base material's mechanical strength, wear resistance, and fracture toughness can all be improved by mixing with hard ceramic nanoparticles. By adopting Ultrasonic-Cavitation assisted casting technique, an Al6061 alloy composite comprising varied weight percentages of B4C nanoparticles (ranging from zero to eight weight percent) was effectively manufactured. Although the hardness, ultimate tensile strength, and yield strength of the material all augmented significantly, the ultimate strength decreased as the concentration of B4C Nanoparticles increased.

Microstructure and Mechanical Properties of Zrb2/Aa6111 Particle-Reinforced Aluminum Matrix Composites by Friction Stir Processing and Heat Treatment

Microstructure and Mechanical Properties of Zrb2/Aa6111 Particle-Reinforced Aluminum Matrix Composites by Friction Stir Processing and Heat Treatment

Microstructure and thermal properties of binary ceramic particle-reinforced aluminum matrix composites with SiC/LAS

Microstructure and thermal properties of binary ceramic particle-reinforced aluminum matrix composites with SiC/LAS

SiC particle reinforced Al matrix composites brazed on aluminum body for lightweight wear resistant brakes

Aluminum alloys are well known light-weight alloys and very interesting materials to optimize the strength/weight ratio in order to reduce automotive vehicle weight, fuel consumption and CO2 emissions; unfortunately, they are also relatively soft and therefore cannot be used for high wear applications.The aim of this work was to develop an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) joined on to its surface.Different approaches based on brazing or shrink fitting joining technologies were used to join SiC/Al to the aluminum alloy surface.A functional graded structure was built by brazing thin layers of aluminum matrix composites reinforced with progressively higher amount of SiC particles by using a Zn–Al based alloy as joining material. Several samples were prepared by shrink fitting and brazing: 40 mm x 40 mm x 10 mm samples and a 100 mm diameter brake disc with 68% SiC particle reinforced Al matrix surface and aluminum alloy A365 body. Tribological tests demonstrated that an aluminum alloy brake disc with wear-resistant SiC particle reinforced aluminum matrix composites (SiC/Al) brazed on its surface is a promising technical opportunity.

Towards the understanding the effect of surface integrity on the fatigue performance of silicon carbide particle reinforced aluminium matrix composites

The fatigue performance of metal matrix composites (MMCs) is highly related to their surface integrity due to the intensive tool-particle interactions and metallographic alterations of matrix, especially under extreme cutting parameters, which could largely result in surface morphologic defects and subsurface damage on the components. Although the fatigue performance of bulk MMCs has been extensively studied, the influence of machining-induced surface anomalies on the fatigue failure mechanism still needs to be understood. This paper investigates the effect of two distinct surface integrities induced by two cutting regimes (ductile, and semi-brittle regime) on the fatigue performance of MMCs. The ductile and semi-brittle regime were represented by different surface integrities regarding the particle behaviours and their effect on the mechanical and metallographic alterations of matrix materials. In-depth analysis in terms of surface topography, subsurface damage, and residual stresses of the machined workpieces has been carried out before the three-point bending fatigue test. The results showed that the samples machined by finish milling (very low feed – semi-brittle regime) unexpectedly presented lower fatigue lives compared to the rough-milled counterparts (high feed – ductile regime), despite the former displayed compressive residual stress and lower surface roughness. It was found that the particles have pronounced influence on the fatigue performance in two different ways: under low cycle fatigue, the particles were prone to be fractured by the high stress applied (which accelerated the formation of crack initiations and therefore shortened the fatigue life), while under high cycle fatigue, the reinforcement particles were not fractured and instead they could inhibit the crack growth up to some extent. Therefore, fatigue lives of the rough-milled samples (high feed – ductile regime) were enhanced due to the retardation of reinforcement particles.

Droplet Impact-Induced Molten Pool Dynamics and Particle Migration Patterns During TIG-Assisted Droplet Deposition Manufacturing of SiC Particle-Reinforced Al-Si Alloy

A three-dimensional droplet-pool coupled model with dispersed phase (solid SiC particles) was developed to simulate TIG-assisted droplet deposition manufacturing (DDM) of silicon carbide particle-reinforced aluminum matrix composites (AMCs), which was employed to calculate the surface morphology of the deposited layer, the thermal-flow fields and the distribution state of reinforcing particles in the molten pool. The cross-section profile of a single-track SiC-reinforced AMC deposit and the distribution state of reinforcement were examined and compared with the findings predicted by simulation, a good agreement was achieved. It is found that the impacting droplet including the SiC reinforcement creates an obvious crater within the molten pool. The viscous damping and simultaneous solidification are the main factors that dissipate the kinetic energy of the droplet. In addition, we discuss quantitatively how impact-induced thermodynamic within molten pool can change the migration behavior and distribution state of SiC reinforcement. The non-homogeneous distribution of the particles can be attributed to the thermocapillary micro-convection and the velocity difference in the spreading and recoiling stages.