Particle Reinforced Aluminum Matrix Composites Research Articles

Aluminum carbide formation in Al-graphite composites: In situ study and effects of processing variables and sintering method

The particulate-reinforced aluminum–matrix composites are interesting due to their attractive physical and mechanical properties over their monolithic counterparts, which are related to their prominent structural differences. The effect of interfacial reaction on the mechanical properties of the Al composites has been attributed to the influence of the reaction product. In this work, the formation of Al4C3 in Al-Gr compounds prepared by high-energy ball milling and sintered by high-frequency induction is compared with a conventional method of sintering: cold compaction and furnace sintering. The conditions related to the generation of this carbide and a precise temperature in which the initial generation of this phase occurs were determined. The different results and the in-situ characterization using HR-TEM showed the substantial reactivity of graphite in the aluminum matrix, leading to the formation of the Al4C3 phase within a few seconds of heating to 250 °C. The conventionally sintered samples displayed the highest number and size of Al4C3 precipitates. In contrast, the heated sample exhibited varied quantities and sizes of these precipitates. Notably, the high-frequency induction sintered samples contained smaller Al4C3 precipitates with a lower number density. Structural, microstructural, and chemical composition results of this phase formed in Al-Gr composites are also shown.

Joining high volume fraction SiC particle reinforced aluminum matrix composites using Bi2O3-B2O3-ZnO-BaO-Na2O glass

This paper designs a bismuthate glass 58Bi2O3-25B2O3-13ZnO-2BaO-2Na2O in mol%(BBZ) and uses it to join 65 % volume fraction SiC particle reinforced aluminum matrix composites (65 vol%SiCp/ZL102) in an atmospheric environment. The thermal properties of BBZ glass were studied, and the effect of the brazing process on the mechanical properties of the joint was explored. The results show that the glass transition temperature of the glass is 344.6 °C, and the two crystallization temperatures are 464.7 °C and 544.3 °C. The oxidation of the parent material can improve the mechanical properties of the joint. The increase in welding temperature and the extension of holding time make the mechanical properties of the joint first increase and then decrease. When brazing at 490 °C for 30 min, the pre-oxidized composite material was brazed, the joint was defect-free, and the shear strength of the joint was 19.4 MPa. The analysis of the shear fracture showed that the fracture mainly occurred in the glass brazing material, which is a brittle fracture.

Pulsed Laser Ultrasonic Vibration-Assisted Cutting of SiCp/Al Composites through Finite Element Simulation and Experimental Research

Silicon carbide particle-reinforced aluminum matrix composites (SiCp/Al) find diverse applications in engineering. Nevertheless, SiCp/Al exhibit limited machinability due to their special structure. A pulsed laser ultrasonic vibration assisted cutting (PLUVAC) method was proposed to enhance the machining characteristics of SiCp/Al and decrease surface defects. The finite element model was constructed, considering both the thermal effect of the pulsed laser and the location distribution of SiC particles. The model has been developed to analyze the damage forms of SiC particles and the formation mechanisms for the surface morphology. The influence of pulsed laser power on average cutting forces has also been analyzed. Research results indicate that PLUVAC accelerates the transition from the brittleness to the plastic of SiC particles, which helps to reduce surface scratching caused by fragmented SiC particles. Furthermore, the enhancement of surface quality is attributed to the decrease in surface cracks and the beneficial coating effect of the Al matrix. The accuracy of the simulation is verified by experiments, and the feasibility of PLUVAC method to enhance the surface quality of SiCp/Al is confirmed.

Damping and mechanical properties of SiC particles reinforced aluminium matrix composites prepared by colloidal dispersion and suction filtration method

In order to uniformly distribute SiCp in the aluminium matrix and prepare SiCp/Al composites with high mechanical and damping properties, a preparation method of colloidal dispersion and suction filtration was developed. It was observed from the microstructure of the composites that the SiCp/Al composites prepared by colloidal dispersion and suction filtration method had good interfacial structures, and the interfacial reaction between SiCp and aluminium matrix was effectively inhibited. Tensile mechanical properties at room temperature and damping properties in the temperature range of 25 °C to 300 °C were tested for the SiCp/Al composites with volume fractions of 5% to 10%. The results showed that SiCp/Al composites have excellent mechanical and damping properties when the volume fraction of SiCp was 7%. This is because SiCp were uniformly distributed in the aluminium matrix, and formed a good interfacial bond with the aluminium matrix, which benefitted both the interfacial slip loss and the strengthening effect of SiCp.

Agglomerating behavior of in-situ TiB2 particles and strength-ductility synergetic improvement of in-situ TiB2p/7075Al composites through ultrasound vibration

Agglomerates of in-situ particles are the key detrimental defects in particulate reinforced aluminum matrix composites (PRAMCs) by acting as Achilles' heel leading to the premature failure of the materials. Effective methods to disperse/eliminate these agglomerates rely on in-depth understanding of the agglomeration mechanism of the in-situ particles. In this work, the agglomerating behavior of TiB2 particles in Al-Ti-B system was investigated through the thermit reactions between mixed fluorides and molten aluminum. The results indicate that the morphological patterns of TiB2 agglomerates are inherited from the preformed Al3Ti intermedium. The formation of flocculent, shell and flaky TiB2 agglomerates are the results of the diffusing boron atoms continuously reacting with Al3Ti. The in-situ Al-TiB2 was used as a precursor to prepare TiB2p/7075 Al composites. In particular, ultrasound vibration treatment was applied to explore if a locally forced oscillation can deagglomerate the TiB2 agglomerates. Microstructural observations strongly support such speculation. Thanks to the deagglomeration and dispersion of TiB2 particles, both the strength and ductility of the PRAMC have been improved drastically. The fracture surface of the composites was transformed from particle debonding to the dominance of ductile fracture.

Phase composition and microstructure of B4C particles reinforced aluminum matrix composites fabricated via direct laser deposition

Phase composition and microstructure of B4C particles reinforced aluminum matrix composites fabricated via direct laser deposition

Investigations on tensile mechanical properties of rigid insulation tile materials at elevated temperatures based on digital image correlation algorithm

This work investigates the tensile mechanical properties of rigid insulation tile (RIT) materials at room temperature (26 °C) and elevated temperatures (700–1000 °C) through experimental and digital image correlation (DIC) methods. Experimental results indicate that the tensile strength of RIT materials changes nonlinearly with increasing temperature and that the primary fracture mode under tension load is fiber root fracture. In terms of the DIC algorithm, this work builds an elevated-temperature DIC test system. A zero-mean Gaussian filtering algorithm and an image gradient difference square sum algorithm (SSDGI) are proposed to improve the precision of the DIC algorithm. The derived tensile stress-strain curve of RIT materials reveals that the elastic modulus changes nonlinearly with increasing temperature. The reliability and precision of the DIC algorithm are confirmed through the tensile test of silicon carbide particle-reinforced aluminum matrix composites. Hence, this work provides guidance for evaluating mechanical properties of RIT materials under elevated temperature environments.

Hot Deformation Behavior and Mechanisms of SiC Particle Reinforced Al-Zn-Mg-Cu Alloy Matrix Composites

A systematic and comprehensive analysis of the hot deformation and mechanisms of SiC particle-reinforced aluminum matrix composites is significant for optimizing the processing of the composites and obtaining the desired components. Based on this, related research on 11 vol% SiCp particle-reinforced 7050Al matrix composites was carried out. Hot compression experiments were carried out on the Gleeble-3500 thermal simulator to study the hot deformation behavior of composites at the temperature of 370–520 °C and strain rate of 0.001–10 s−1. The hyperbolic sine constitutive equation of the material was established, and the processing map was calculated. Combining the typical metallograph and misorientation angle distribution, the microstructure evolution mechanism of composites was analyzed, and the effect of particles on recrystallization behavior was investigated. Under certain process conditions, the dominant deformation mechanism of composites changed from dynamic recovery (DRV) to dynamic recrystallization (DRX), and the grain boundary sliding mechanism began to play a role. In addition, high temperature tensile and elongation at break were tested, and it was found that the dominant form of fracture failure changed from brittle fracture of the particles to ductile fracture of the matrix as the temperature increased.

Effects of solution temperatures on microstructures and mechanical properties of B4C/7A04Al composites: A comparison study with 7A04Al alloys

To prepare particle-reinforced aluminum matrix composites with ultra-high strength, high-strength 7xxx Al alloys are commonly employed as matrices. Heat treatment plays a crucial role in enhancing the mechanical properties of the alloys and their composites, but the influence of solution temperatures on composites based on 7xxxAl alloys remains unexplored. In this study, the effects of solution temperatures on the microstructures and mechanical properties of B4C/7A04Al composites fabricated via powder metallurgy (PM) technology were investigated, as well as those of 7A04Al alloys for comparison. Before solution treatments, the prominent second phases in the composite were MgZn2 phases, while those in the 7A04Al alloy consisted of MgZn2 and Al2CuMg phases. At lower solution temperature (420 °C), MgZn2 phases dissolved completely, whereas Al2CuMg phases persisted. Al2CuMg phases dissolved at 450 °C, and thus the 7A04Al alloy obtained the optimum strength and elongation. Further elevating the solution temperature caused abnormal grain growth (AGG) in the 7A04Al alloy, leading to a deterioration of strength and plasticity. In contrast, at various solution temperatures, the composite exhibited stability in grain size, which could be attributed to the pinning effects of B4C particles and Mg(Al)B2 phases, the reaction products between the boron impurity and the Al matrix. However, at higher solution temperatures (510 °C and 600 °C), the segregation of Mg and O around B4C particles was aggravated, and thus the elongation of the composite deteriorated. Interestingly, the strength remained relatively unaffected due to the strengthening effects of Mg(Al)B2 phases. The results indicate that the composite exhibited a broad range of solution temperature with comparable strength and elongation across a temperature range of 420 °C–470 °C. But for the 7A04Al alloy, the optimal solution temperature is 450 °C.

Tribological and corrosion characteristics of tetra hybrid particulate-reinforced aluminum composites for aerospace and automotive applications

This study investigates Hybrid Particulate-Reinforced Aluminum Matrix Composites (HPRAMCs), a material class known for exceptional physico-mechanical, tribological, and corrosion resistant properties. The research synthesizes HPRAMCs using SiC, Al2O3, graphite (Gr), and sugar cane bagasse ash (SCBA) reinforcements through a powder metallurgy process, followed by sintering at 550°C for 3 h. Comprehensive tests include X-ray diffraction (XRD) for phase analysis, physico-mechanical assessments, tribological evaluations, and corrosion resistance analyses. Notably, secondary reinforcements significantly reduce porosity, with AS4 HPRAMC exhibiting a 0.53% porosity, while AS1 HPRAMC has 1.446%. AS4 HPRAMC displays a remarkable 209.76% increase in compressive strength and a 446.40% boost in material hardness compared to pure aluminum. Secondary reinforcements also improve tribological performance, reducing wear loss by 60.27% and the coefficient of friction by 89.89%. Exceptional corrosion resistance, with an inhibition efficiency of 99.691%, is observed in the AS4 HPRAMC sample, confirmed by scanning electron microscopy (SEM). These findings underline the substantial potential of HPRAMC materials, positioning them as promising candidates for aerostructural components, aircraft systems, automobiles, spacecraft, and high-performance engineering applications.

Effects of laser power on the microstructural evolution and mechanical performance in laser dissimilar welding of TC4 to SiCp/6092Al composite

In this study, an overlap configuration for Ti6Al4V alloy (TC4) and SiC particle reinforced aluminum matrix composites (AMC) was achieved by laser welding process. The influence of laser power on the microstructural evolution, intermetallic compounds formation and mechanical properties of TC4/AMC joints were investigated. The presence of reinforced phase SiC complicated the metallurgical reaction in the molten pool, resulting in the formation of intermetallic compounds, such as Al4C3, TiC, TiAl, and TiAl3. The influence of laser power was more pronounced on the penetration depth compared to its impact on the weld width. The thickness of TiAl intermetallic compounds at the TC4/AMC interface increased as the laser power was raised. Abundant dislocations existed surrounding the TiAl3 phase because of the different thermal-mechanical properties between Al matrix and TiAl3 phase. The tensile shear force of TC4/AMC joints can be considerably improved by reducing the thickness of the TiAl3 phase. The maximum tensile shear force of 1675.6 N for the TC4/AMC joint was obtained at a laser power of 1500 W when the thickness of the TiAl3 layer reached the lowest value of 7.1 μm. The research results have the potential to improve laser welding techniques for TC4/AMC hybrid structures and provide valuable guidance for the design of TC4/AMC welded joints in the future.

Experimental analysis and machining characterization of aluminium 356 matrix composites reinforced with fly ash and alumina oxide Al2O3

A higher specific strength, specific modulus, damping capacity, and robust wear resistance are among the many superior properties of metal matrix composites (MMCs) over unreinforced alloys. A growing body of research is focused on low-density composites with low-cost reinforcements. Regarded as one of the least costly and least dense reinforcements available in substantial quantities, fly ash is a solid waste by product that is created when coal is burned in thermal power plants. Using Al356, Fly Ash, and Alumina Al2O3, the proposed metal matrix composite is created. Consequently, it is expected that fly ash reinforced composites will break through the financial barrier and become widely used in automobile and small engine parts. The primary objective of this research is to explore the potential of fly ash-reinforced composites to overcome economic barriers and find extensive applications in automotive and small engine components. By incorporating fly ash particles into aluminum alloy, we aim to not only enhance the properties of the material but also promote a sustainable use for this abundant waste by product. To achieve our goals, we employ a comprehensive fabrication process involving the incorporation of fly ash into the aluminum matrix using stir-casting techniques. This method allows for effective mixing and the formation of composite materials with the desired properties.. Particle reinforced aluminium matrix composites are becoming more and more popular for the creation of secondary components because of their low cost, isotropic properties, and chance for secondary processing. With fly ash, an easily accessible industrial waste, mixed with aluminum and stir-cast to form composite materials, the current effort aims to identify a workable use for this material.

Revealing the Influence of SiC Particle Size on the Hot Workability of SiCp/6013 Aluminum Matrix Composites.

SiC particle (SiCp) size has been found to significantly influence the hot workability of particle-reinforced aluminum matrix composites (AMC). In this work, therefore, three types of SiCp/6013 composites with different SiCp sizes (0.7, 5 and 15 μm) were prepared and then subjected to isothermal hot compression tests. In addition, constitutive analysis, processing maps and microstructural characterizations were used to reveal the influence of SiCp size on the hot workability of SiCp/6013 composite. The results showed that the values of hot deformation activation energy Q increased with decreasing SiCp size. Specifically, at lower temperatures (e.g., 350 and 400 °C), the highest peak stress was shown in the AMC with SiCp size of 0.7 μm (AMC-0.7), while in the AMC with SiCp size of 5 μm (AMC-5) at higher temperatures (e.g., 450 and 500 °C). This is because a finer SiCp size would lead to stronger dislocation pinning and grain refinement strengthening effects, and such effects would be weakened at higher temperatures. Further, dynamic softening mechanisms were found to transform from dynamic recovery to dynamic recrystallization with increasing SiCp size, and the dynamic recrystallization occurred more easily at higher temperatures and lower strain rates. Consequently, the instability zones of the composites are all mainly located in the deformation region with lower temperature and higher strain rate, and smaller SiCp results in larger instability zones.

Macro-micro analysis of mechanical properties of Al0.6CoCrFeNi high-entropy alloy particle-reinforced Al-based composites

In this study, Al0.6CoCrFeNi high-entropy alloy particle-reinforced 5052Al-based composites with good surface morphology and different diffusion layer thicknesses were successfully prepared using hot-press sintering and annealing, which were subsequently characterized by XRD, SEM, EBSD, micropillar compression, and nanoindentation. The EBSD tests indicate that the Al0.6CoCrFeNi high-entropy alloy has a dual-phase crystal structure with the presence of both FCC and BCC phases inside, and the internal grain size is significantly higher than that of the matrix. Subsequently, the mechanical property mapping images of the particle-diffusion layer-matrix region on the composite surface were obtained using the NanoBlitz 3D method in the nanoindentation experiments. And based on the particle and matrix mechanical property parameters obtained by nanoindentation experiments, they were fitted into different mathematical models to obtain the hardness and elastic modulus of the composite. As a result, the correlation was found to be linear, and the slope of the fitted straight line increased gradually with the prolongation of the annealing time. In conclusion, it is evident from the comparison of the results of mathematical model fitting of mechanical property parameters with the results of macroscopic mechanical property tests that the P. G. Klemens model exhibits an excellent fitting effect on the macro-microscopic mechanical properties of particle-reinforced aluminum matrix composites compared with other models such as the rule of mixtures.

Comparison of microstructural, texture and mechanical properties of SiC and Zn particle reinforced FSW 6061-T6 aluminium alloy

This work investigates the microstructure, mechanical characteristics, and texture evolution of friction stir welding (FSW) of AA6061-T6 metal matrix composites (MMCs) reinforced with silicon carbide (SiC) and zinc (Zn) particles. The SZ region of the SiC and Zn particle-reinforced aluminium matrix (Al-matrix) composites has ultra-fine grain refinements of 4.79 and 4.18 μm, respectively, compared to base metal (BM) particle sizes of 44.97 μm. Ultra-fine grain refinement in the SZ zone produces dynamic recrystallization with particulate-driven nucleation, Zenner Hollomon, and homogeneous SiC/Zn particle distribution in the Al-matrix. Recrystallization texture components P {011} <112>, cube {001} <101>, rotating cube (H) {001} <110>, and F {111} <112>, along with primary shear texture components (B/B¯, and C), suggested DRX at the joint interface in the SiC-reinforced Al-matrix composite. However, the Zn-reinforced Al-matrix composite has a high plain strain, recrystallization, and deformation texture components of copper {112} <111>, Brass {011} <211>, cube {001} <101>, Goss {110}, and P 011 <112>, and major shear texture components (B/B¯ and C). SiC and Zn-reinforced Al-matrix composites have 110 ± 4 and 120 ± 5 HV0.2 average microhardness, respectively. Also, SiC and Zn-reinforced Al-matrix composites have 224 and 236 MPa tensile strengths, respectively.

Effect of Al2O3 particle content on microstructure and mechanical properties of 1060Al/Al–Al2O3 composites fabricated by cold spraying and accumulative roll bonding

1060Al/Al–Al2O3 laminated particle-reinforced aluminum matrix composites (LPRAMCs) were successfully prepared using a combination of cold spraying (CS) and accumulative roll bonding (ARB) techniques, exhibiting a synergistic improvement in strength and plasticity. The effects of Al2O3 particle content on the microstructure, tensile properties and fracture morphology of LPRAMCs were studied. The results showed that compared with the 1# composites with higher Al2O3 particle content (20.1 vol%), the 2# composites with lower Al2O3 particle content (8.4 vol%) exhibited delayed necking fracture during the ARB process, with greater elongation (El) but lower ultimate tensile strength (UTS). After 5 passes of ARB, the UTS and El of the 1# and 2# composites were 345 MPa, 16.1%, and 293 MPa, 22.2%, respectively. This suggests that the mechanical properties of the Al–Al2O3 deposited layer have a significant impact on the mechanical properties of LPRAMCs. With an increase in ARB passes, the fracture mode of the LPRAMCs shifted from brittle to ductile fracture, displayed by equiaxed and shear dimples. These findings can provide novel insights and theoretical foundations for optimizing the mechanical properties of Al matrix composites.

Experiment and mechanism investigation on the effect of heat treatment on residual stress and mechanical properties of SiCp/Al–Cu–Mg composites

Low-volume fraction particle-reinforced aluminum matrix composites (PRAMCs) are commonly prepared using powder metallurgy (PM) technology, followed by heat treatment processes to improve the performance of PRAMCs. PRAMCs are prone to produce significant uneven residual stresses during the quenching process. It is difficult to eliminate the quenching residual stress of PRAMCs via the heat treatment process of the matrix aluminum alloy. Therefore, this study systematically investigates the effects of solid solution and artificial aging treatment processes on residual stress, mechanical properties, and microstructure of SiCp/Al–Cu–Mg composites through orthogonal and single-factor experimental methods. After optimizing the heat treatment process, minor residual stress with a 71.6% von Mises residual stress relief rate and good comprehensive mechanical properties are achieved. Based on the experimental results, macro and micro mechanisms of residual stress evolution and strengthening of SiCp/Al–Cu–Mg composites during heat treatment are revealed, providing valuable insights into the process of heat treatment of PRAMCs.

Manufacturing SiCp/Al composites by semi-solid metal direct writing based on mixed powder remelting

Stir casting and powder metallurgy are the mainstream technologies for manufacturing particle-reinforced aluminum matrix composites. However, particle agglomeration and extensive interfacial reaction in stir casting, as well as residual porosity in powder metallurgy, make it challenging to obtain the due performance. In this study, a semi-solid metal direct writing process based on mixed powder remelting was proposed to manufacture SiCp/Al composites. The mixed powder consisting of AlSi10Mg alloy powder, pure Al powder, and SiCp is heated to a temperature slightly exceeding the melting point of the alloy powder and then sheared to produce a paste-like semi-solid aluminum slurry with suspended SiCp. The microstructures of SiCp/Al composites were experimentally investigated and modeled, demonstrating the uniformity of SiCp and the designability of microstructural characteristics (i.e., the volume fraction and shape factor of the solid phases). The SiCp-matrix interface was also characterized to illustrate the reliable interfacial bonding due to the relatively low processing temperature. Compared with the mentioned processes, this novel approach shows superiorities in particle dispersion and interfacial reaction control.

Preparation and mechanical behavior of Co‐based hard particles reinforced aluminum matrix composites

Preparation and mechanical behavior of Co‐based hard particles reinforced aluminum matrix composites

Towards Closed-Loop Recycling of Ceramic Particle-Reinforced Aluminium Alloys: Comparative Study of Resistance-Heating Sintered Primary and Solid-State Recycled Secondary SiCp/AlSi7Mg Composites

Particle-reinforced aluminium matrix composites (AMC) with a high-volume fraction of ceramic reinforcement (&gt;30 vol.%) combine high specific strength and stiffness with good wear resistance and thermal stability, resulting in their increasing popularity in high-load applications, such as brake discs and bearings. It is hence assumed that AMC will accumulate as scrap in the near future. Appropriate recycling strategies must therefore be developed to maintain AMC’s inherent properties. Melt-metallurgical recycling routes bear the danger of dissolving the ceramic reinforcement in the liquid metallic matrix and contaminating primary melts or forming intermetallic phases in secondary melts. Here, a solid-state AMC recycling route with crushing and sintering is investigated, wherein all steps are carried out below the solidification temperature of the aluminium matrix. A sintered primary AMC is mechanically converted into a particulate/powdery secondary raw AMC in coarse, medium, and milled quality (i.e., with d ≈ 7–12 mm, d ≈ 3–7 mm, and d &lt; 300 µm) and subsequently resistance heating sintered to a secondary AMC under a variation of the sintering pressure. The two AMC generations are analysed and discussed regarding their microstructure and mechanical properties. Since the secondary AMC show reduced the mechanical strength, the fracture surfaces are analysed, revealing iron contaminations from the mechanical processing.