Particle Reinforced Aluminum Matrix Composites Research Articles

Effect of rotational speed on friction stir welding microstructure and properties of cast and rolled (ZrB2 + Al3Zr) particle-reinforced aluminum matrix composites

Effect of rotational speed on friction stir welding microstructure and properties of cast and rolled (ZrB2 + Al3Zr) particle-reinforced aluminum matrix composites

Study on the Critical Conditions for Ductile-brittle Transition in Ultrasonic-assisted Grinding of SiC Particle-reinforced Al-MMCs

High volume fraction (45 %) silicon carbide particle-reinforced aluminum matrix composites (SiCp/Al-MMCs) play a significant role in various engineering fields due to their outstanding performance. However, damages characterized by SiC particle fracture during machining lead to poor surface integrity, which severely affects the fatigue performance of SiCp/Al composite structural components. Ultrasonic-assisted grinding (UAG) is acknowledged as beneficial for promoting ductile grinding in hard and brittle materials. This study focuses on the critical conditions for ductile-brittle transition in ultrasonic-assisted grinding of SiCp/Al composites and develops a mechanism and data driven model of critical undeformed chip thickness (UCT) for ductile grinding to accurately predict the material removal mode. The model thoroughly integrates considerations of chip morphology, removal mode transition mechanism, and grinding surface damage characteristics. Response surface methodology (RSM) and genetic algorithms (GA) were utilized to correct the impact of processing parameters on the removal regime. Experiments on ultrasonic-assisted side and end grinding were conducted to thoroughly discuss the effects of different undeformed chip thicknesses, grinding speeds and ultrasonic vibration amplitude on surface damage and the critical conditions for the ductile-brittle transition. The findings corroborate the experimental data with the predicted values. Ultrasonic vibration can effectively reduce the brittle fracture of SiC particles in SiCp/Al composites. Appropriately increasing the grinding speed and reducing the chip thickness can enhance the critical chip thickness for ductile grinding and decrease the proportion of brittle surfaces, thereby achieving a balance between surface integrity and grinding efficiency. This research provides guidance for high-performance machining of SiCp/Al composites.

Optimization of Tool Wear and Cutting Parameters in SCCO2-MQL Ultrasonic Vibration Milling of SiCp/Al Composites

Silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites are significant lightweight metal matrix composites extensively utilized in precision instruments and aerospace sectors. Nevertheless, the inclusion of rigid SiC particles exacerbates tool wear in mechanical machining, resulting in a decline in the quality of surface finishes. This work undertakes a comprehensive investigation into the problem of tool wear in SiCp/Al composite materials throughout the machining process. Initially, a comprehensive investigation was conducted to analyze the effects of cutting velocity vc, feed per tooth fz, milling depth ap, and milling width ae on tool wear during high-speed milling under SCCO2-MQL (Supercritical Carbon Dioxide Minimum Quantity Lubrication) ultrasonic vibration conditions. The results show that under the condition of SCCO2-MQL ultrasonic vibration, proper control of milling parameters can significantly reduce tool wear, extend tool service life, improve machining quality, and effectively reduce blade breakage and spalling damage to the tool, reduce abrasive wear and adhesive wear, and thus significantly improve the durability of the tool. Furthermore, a prediction model for tool wear was developed by employing the orthogonal test method and multiple linear regression. The model’s relevance and accuracy were confirmed using F-tests and t-tests. The results show that the model can effectively predict tool wear, among which cutting velocity vc and feed rate fz are the key parameters affecting the prediction accuracy. Finally, a genetic algorithm was used to optimize the milling parameters, and the optimal parameter combination (vc = 60.00 m/min, fz = 0.08 mm/z, ap = 0.20 mm) was determined, and the optimized milling parameters were tested. Empirical findings suggest that the careful selection of milling parameters can significantly mitigate tool wear, extend the lifespan of the tool, and enhance the quality of the surface. This work serves as a significant point of reference for the processing of SiCp/Al composite materials.

Evolution process of T1 precipitate in Al–Cu–Li–TiC/TiB2 alloy during aging treatment

In this study, particle-reinforced aluminium matrix composites (PRAMCs) of an Al–Cu–Li alloy were prepared using nano-sized TiB₂+TiC particles. The relationship between TiB₂+TiC nanoparticles and T1 precipitates during the ageing process, as well as the influence of TiC + TiB₂ particles on the growth process of T1 precipitates during the ageing process, were investigated. The grain sizes of the A0 and A1 samples were found to be 249.89 μm and 86.42 μm, respectively. The dislocation density is greater in the deformed A1 sample. The coefficient of thermal expansion (CTE) effect generated by TiC and TiB₂ particles stimulates the precipitation process of T1 precipitates. The A1 alloy reached the peak ageing state in a shorter time and yielded a greater number of T1 precipitates. The precipitation process of T1 precipitate is: SSSS→T1P→T1. The transition from T1P (face-centered cubic, FCC) to T1 (hexagonal close packing, HCP) entails a modification in the order of packing. The recently formed T1P precipitate is attached to the established T1 precipitate and extends along the c-axis through the shared copper-rich layer that has formed on both sides of the mature T1 precipitate. The mechanical properties of sample A1 are optimal at T = 22h, with a yield strength, tensile strength, and elongation of 520 MPa, 553 MPa, and 8.2%, respectively. In comparison to the A0 sample, the yield strength and tensile strength exhibited an increase of 5.05% and 5.13%, respectively.

Study of bond strength and electronic properties at the 6H-SiC/Al interface: Based on first-principles calculations

As the medium between the reinforcement and the matrix, the interface plays a critical role in the mechanical properties of silicon carbide particle reinforced aluminum matrix composites. This study used first-principles calculation methods to systematically analyze 14 different 6H-SiC/Al low-index interfaces, including atomic configuration, interface bonding strength, and electronic structure and bonding principles between interfaces. The adhesion work calculations reveal that the C-top-SiC(0001)/Al (111) and SiC(0001)/Al (100) interfaces have larger adhesion work values, specifically 5.09 J/m2 and 5.021 J/m2, respectively. Additionally, the rigid tensile testing confirms that the tensile stress values at the interfaces of C-top-SiC(0001)/Al (111) and SiC(0001)/Al (100) are higher, measuring 36.4 GPa and 32.5 GPa, respectively. The above results show that the interface bonding strength of these two configurations is the highest, the most stable, and most likely to appear in the 6H-SiC/Al interface configuration. The results of the analysis on charge density difference and partial density of states indicate that the interfaces of C-top-SiC (0001)/Al (111) and SiC (0001)/Al (100) are primarily composed of strong ionic and covalent bonds.

Direct aging treatment of TiN modified Al–Mn–Sc alloy processed by laser powder bed fusion: On the microstructure evolution and mechanical property enhancement

In this study, the TiN nanoparticles modified Al–Mn-Sc composite and Al–Mn-Sc alloy have been fabricated by the laser powder bed fusion (LPBF). The microstructure, mechanical properties and strengthening mechanisms of these materials were discussed in details for both the as-built and artificial aged conditions. The results showed that the aged Al–Mn-Sc/TiN composite exhibits homogeneous nucleation with equiaxed grains ranging from 0.81 μm to 1.30 μm. After direct aging treatment of 300 °C, there are a volume fraction of secondary L12-Al3(Ti, Sc, Zr) nanoparticles precipitated in the composite sample, contributing to an ultra-high fracture strength of 701 ± 16 MPa. The increment in strength brought by TiN mainly comes from fine grains and high volume fraction of L12-Al3(Ti, Sc, Zr) nanoprecipitates. The fracture behaviors suggest that the uniform distribution of reinforced particles and less amount of micro pores can improve the strength and ductility of LPBF particle reinforced aluminum matrix composites.

Enhanced strength–ductility synergy of SiC particles reinforced aluminum matrix composite via dual configuration design of reinforcement and matrix

To overcome the strength-ductility conflict in particle reinforced aluminum matrix composites (PRAMCs), a novel dual configuration strategy of microstructure was proposed in this work. The dual configuration including both heterogeneous grain structure and hybrid reinforcements was obtained by powder metallurgy, which was designed as submicron-sized SiC particles (SiCsm)/Al and micron-sized SiC particles (SiCm)/2024Al components. Representative alternating coarse grain (CG) bands containing SiCm and ultra fine grain (UFG) bands with dispersed SiCsm were revealed in microstructural characterizations. Compared to corresponding homogeneous composites with the same fraction particles, the dual configuration composite achieved simultaneous enhancement in strength and ductility and remained a comparable Young’s modulus of 98GPa, which represented 442 MPa in yield strength, 590 MPa in ultimate strength and 8.7 % in fracture elongation. The extra strength provided by hetero-deformation induced (HDI) strengthening is a potential dominant strengthening mechanism. The intrinsic toughening mechanisms primarily contribute to HDI strain hardening and enhanced dislocation accumulation capacity, while the extrinsic toughening mechanisms presumably attribute to more uniform microcrack distribution and blunting effect of CG zones on cracks. Our work provides a feasible route including ball milling and powder assembly to preparate high-modulus aluminum matrix composites for strength-ductility balance design.

Study on the microstructure and mechanical properties of hot rolled nano-ZrB2/AA6016 aluminum matrix composites by friction stir processing

In this paper, in-situ ZrB2/AA6016 particle-reinforced aluminum matrix composites were prepared in molten A6016 aluminum alloy melt by KBF4-Al- K2ZrF6 reaction system. For the first time, this paper presents that after casting, the composites would be subjected to large strain hot rolling (LSHR) with 60 % undercutting and then friction stir processing (FSP) with a stirred probe speed of 1200 r/min and a traveling speed of 60 mm/min. To study the microstructure and mechanical properties of composites strengthened by large strain hot rolling combined with friction stir processing. The results show that the tensile strength of the base material is 140.1 MPa, the elongation is 46.3 %, the product of strength and elongation reaches 6.5 GPa%, and the average hardness is 43.4 HV; The tensile strength of LSHR+FSP nugget zone is 163.4 MPa, the elongation is 78.9 %, the product of strength and elongation reaches 12.9 GPa %, which is about 98.6 % higher than the base material, and the average hardness is 59.8 HV, which is about 37 % higher than the base material. SEM, EBSD, and TEM analyses showed that the average grain size is refined from 189.7 μm to 3.8 μm after LSHR+FSP. The ZrB2 particles are sufficiently fragmented, with a particle size of about 20 nm, and uniformly dispersed in the matrix. This study provides the theoretical and experimental basis for applying nanoscale ZrB2 particles reinforcing ultrafine crystalline aluminum matrix composites prepared by LSHR + FSP.

Numerical simulation study on hot pressing of ceramic/metal powders

This study utilizes the multi-particle finite element method (MPFEM) to establish 2D and 3D hot pressing models for particle-reinforced aluminum matrix composites. The hot pressing of 6061Al powder and 10 % volume fraction SiCp/6061Al composite powder are simulated under a temperature range of 430–510 °C and pressures ranging from 15 to 30 MPa. The densification mechanism of the composites is elucidated by analyzing the evolution of density and microscopic particle behavior. The analysis reveals that elevating both the pressing temperature and pressure effectively increases the relative density of the powders, with the maximum growth rate occurring at 25 MPa. Notably, the barrier effect created by SiC particles in the 6061Al matrix restricts the plastic deformation and flow of matrix particles, leading to a lower final relative density for the composite powder compared to pure 6061Al powder. Microscopic observations indicate that particle rearrangement dominates in the initial pressing stage, while plastic deformation and particle flow become crucial factors for enhancing relative density in the later stage. Further stress-strain analysis demonstrates that 6061Al particles effectively fill pores through plastic deformation, resulting in stress concentration primarily on the harder SiC particles.

Electrochemical behavior and microstructural characterization of nano-SiC particles reinforced aluminum matrix composites prepared via friction stir processing

The present work aims to elucidate the mechanism of microstructural evolution in different regions of nano-SiC particles reinforced aluminum matrix composites prepared by friction stir processing (FSP) on its electrochemical behavior. Electron backscatter diffraction technique (EBSD) and transmission electron microscopy (TEM) were employed to characterize the microstructure evolution of stir zone (SZ), advancing side thermomechanically affected zone (AS-TMAZ), retreating side thermomechanically affected zone (RS-TMAZ) and base metal (BM). The electrochemical behaviors of the above zones were investigated using electrochemical tests. A homogeneous and fine microstructure is formed in SZ, not only the nano-SiC is homogeneously distributed within the grains with an average grain size of 3.5 μm, but also the recrystallized grains account for the highest percentage of 85 %. The potentiodynamic polarization curve indicates that the corrosion current densities of the BM, RS-TMAZ, AS-TMAZ and SZ are 0.89, 0.39, 0.85 and 0.36 μA/cm2, respectively, while the polarization impedances are 33.40, 51.42, 48.72 and 73.79 kΩ cm2, respectively. Combining the Nyquist and Bode plots analysis, the optimal electrochemical corrosion resistance is in SZ. The fine and homogeneous recrystallized grains in SZ significantly improve its electrochemical corrosion resistance. This is mainly ascribed to the increase in crystal defects as a result of the increase in grain boundaries, elevating the electron scattering. Simultaneously, the increase in high-energy state grain boundaries is beneficial to the rapid formation of a thicker passivation film.

Effect of Dynamic Recrystallization Mode on Texture Components and Hardness for Nano-SiC Particles Reinforced Aluminum Matrix Composites Prepared Via Friction Stir Processing

Effect of Dynamic Recrystallization Mode on Texture Components and Hardness for Nano-SiC Particles Reinforced Aluminum Matrix Composites Prepared Via Friction Stir Processing

Selection of groove dimension in the fabrication of particulate reinforced aluminium matrix composites using friction stir welding

Selecting groove dimensions has always been challenging for fabricating particulate reinforced aluminium matrix composites using friction stir welding. To address this, heat transfer physics coupled with the level set method was used to estimate material mixing between 6061-T6 Al-matrix and Al2O3 using the COMSOL Multiphysics tool. Groove dimensions of 2 mm width and depth resulted in the absence of volumetric/tunnel defects, nearly symmetric distribution, and minimal agglomeration of Al2O3 powder particles. This combination achieved an optimum trade-off between strength and ductility.

Research on the Ablation Resistance of TiC Particle-Reinforced Aluminium-Based Composite Coatings on Armature Surface

The work aims to enhance and modify the armature surface in electromagnetic rail launch systems and improve its anti-ablation performance to better resist the impact ablation effects of high-temperature and high-speed arcs during the electromagnetic rail launch process and improve launch reliability. TiC particles are widely selected as metal material reinforcements, with advantages such as high melting points and high hardness. In this paper, the arc impact model of pure aluminum alloy and the arc impact model of TiC particle-reinforced aluminum-matrix composite coating–pure aluminum alloy were constructed based on molecular dynamics simulation. The ablation resistance of the material was evaluated by analyzing the depth of arc impact, the mass loss of the model, the number of gasification atoms, and the surface temperature of the material. The protection mechanism of the modified layer on the substrate was revealed by analyzing the damage degree of the surface and subsurface of the material after arc impact. The results showed that the strengthening mechanism of TiC particle-reinforced aluminum-matrix composites included fine grain strengthening, dispersion strengthening, dislocation strengthening, and so on. Covering TiC particle-reinforced aluminum-matrix composite coating on the surface of aluminum alloy armature is helpful in improving its ablation resistance. The research results can provide a theoretical basis and technical support for the modification design and performance control of electromagnetic rail armature.

Hybrid additive manufacturing of aluminum matrix composites with improved mechanical properties compared to extruded counterparts

Great difficulties existed in fabricating large components of SiC particles reinforced aluminum matrix composites with excellent mechanical properties using existing manufacturing procedures. This study demonstrated that the challenges can be addressed by developing a hybrid solid-state additive manufacturing method. The influence of the deposition procedures and the post-processing heat treatment on the microstructure and mechanical properties of the SiC particles reinforced 2009 aluminum ally matrix composites (SiCp/2009Al composites) was systematically investigated using advanced technologies such as spherical aberration corrected transmission electron microscope, atom probe tomography, etc. The results showed that the SiCp/2009Al composites produced by the hybrid solid-state additive manufacturing exhibited enhanced tensile properties and improved isotropy in mechanical properties compared to the extruded feedstock of SiCp/2009Al composites. This was attributed to the formation of dense metal with uniformly distributed SiC particles, high-density of Cu–Mg co-clusters, refined grains and SiC particles, low deformation texture, tightly bonded SiCp/2009Al interface, and sound interfacial bonding between deposited layers.

Evolution of microstructure and mechanical properties of aluminum matrix composites reinforced with dual-phase heterostructures

The trade-off between strength and plasticity has long been challenging in particle-reinforced aluminum matrix composites (PRAMCs). This study proposes an innovative approach for preparing aluminum matrix composites (AMCs) using a dual-phase hybrid of FeCoNiCrMn high entropy alloy (HEA) and multiscale aluminum oxide (Al2O3) particles. The microstructure evolution and strengthening mechanisms were evaluated through scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The results demonstrated that the dual-phase particle strengthening resulted from the alternating distribution and synergistic action of HEA and Al2O3 particles within the matrix, forming a continuous strain buffer with a strength gradient. Notably, introducing HEA and nano-Al2O3 led to a higher density of dislocations. Additionally, EBSD analysis revealed a uniform strain distribution within the AMCs, with a significant concentration of kernel average misorientation (KAM) near the grain boundaries (GBs). In terms of micromechanical properties, the micro-zones of heterogeneous phases exhibit exceptionally high elastic modulus and nanohardness. In terms of macroscopic mechanical properties, the material exhibited impressive ultimate compressive strength and compression ratio values of 447.9 MPa and 37.9 %, respectively. These results represented a remarkable enhancement of 72.1 % and 6.6 % compared to the single FeCoNiCrMn HEA strengthening. Moreover, when applying the HEA + nano-Al2O3 blending mode, the ultimate compressive strength further increased to 506.7 MPa, representing an astonishing boost of 94.7 %. This significant strength improvement can be attributed to effective interfacial bonding, grain refinement, and a high dislocation density resulting from both HEA and Al2O3 particles.

Enhancing strength-ductility synergy of thermally oxidized dual-phase HEA particles reinforced aluminum matrix composites via heterogeneous interface

This work firstly oxidizes single-phase high entropy alloy (HEA) to form FCC and BCC dual-phase structure, and also introduces multi-component nano-oxides on surface to prepare oxidized HEA (OHEA) reinforcements, followed by preparation of OHEA/Al composites by spark plasma sintering. The introduction of O element accelerates interdiffusion between OHEA and Al matrix. FCC phase inside OHEA evolves into soft phase, and BCC matrix phase evolves into hard phase, forming heterogeneous interface in OHEA/Al composites. During tensile process, cracks preferentially initiated in hard phase due to severe stress concentration, and the soft phase effectively retarded crack propagation. Compared with 2024Al matrix, yield strength, tensile strength, and elongation of OHEA/Al composites increased by 35.31%, 57.34%, and 63.33%, respectively, realizing excellent combination of strength and toughness. Grain refinement, thermal mismatch, Orowan, and load transfer strengthenings synergistically improve the performance. The proposed method provides a promising avenue to optimize the properties of composites by pre-oxidizing HEA particles to construct heterogeneous interfacial structure.

Enhancing strength–ductility synergy of AlNp/Al composite by regulating heterostructure of matrix grain and particle distribution

Three heterostructured AlNp/Al composites with different microstructure configurations were fabricated by liquid–solid reaction combined with subsequent thermal-mechanical treatment to obtain a superior strength and ductility combination. The effects of the microstructure configuration including the AlN particle distribution and matrix grain structure on the tensile strength and ductility were studied in detail. The results show that the simultaneous enhancement of tensile strength and ductility can be achieved. The Uniformed-AlNp/Al composite with relatively dispersed particles exhibits a superior ultimate tensile strength of ~387 MPa with an elongation to failure of ~9.1%. It shows an outstanding specific tensile strength and elongation combination compared with other reported particle reinforced aluminum matrix composites. Furthermore, the hetero-deformation induced (HDI) stress has been calculated and is shown to increase significantly in the Uniformed-AlNp/Al composite. It is revealed that the HDI stress plays a crucial role in the significant enhancement of strength and ductility for the AlNp/Al composite.

A comparison of the erosive wear performance of particle reinforced aluminum matrix composites

A comparison of the erosive wear performance of particle reinforced aluminum matrix composites

Research progress on aluminum matrix composites reinforced by medium and high volume fraction hybrid particles

Aluminum matrix composites reinforced with particles offer many advantages, including high specific strength, elevated specific stiffness, reduced thermal expansion coefficient, enhanced thermal conductivity, abrasion resistance, and dimensional stability. These composites find extensive application in aerospace, electronic packaging, and weaponry. The concept of hybrid particle reinforcement, involving multiple reinforcing particles, optimizes the performance attributes of each phase and the synergistic reinforcement effect, leading to potentially superior hybrid particle-reinforced aluminum matrix composites. This paper presents a comprehensive overview of the methods for preparing particle-reinforced aluminum matrix composites. It examines the toughening mechanisms in aluminum matrix composites reinforced with hybrid particles at medium and high volume fractions. These mechanisms include fine grain reinforcement, Orowan reinforcement, and heterogeneous deformation-induced reinforcement, including geometrically necessary dislocation reinforcement. This paper elucidates the role of micronano organizational structures-such as the morphology, size, distribution, and interfacial bonding state of hybrid particles and matrix-in determining the comprehensive performance of aluminum matrix composites. Additionally, it explores the effect of hybrid particle morphology, size, distribution, and micronano structure on the composite’s overall performance. Finally, future research directions and trends in the development of high-performance hybrid particle-reinforced aluminum matrix composites are discussed.

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.