Nanocrystalline High-entropy Alloy Research Articles

Design, preparation and study of microstructure, phase evolution and thermal stability of Ti-Co0.35-Cr0.35-Nb-Zr nanocrystalline HEA for biomedical applications

In the present study, novel Ti-Co0.35-Cr0.35-Nb-Zr high entropy alloy (HEA) has been synthesized by mechanical alloying (MA) followed by sintering at different temperatures. The microstructure and phase stability of as milled powder and sintered samples have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The density and micro-hardness values have also been calculated for the sintered samples. The atomic % of the individual element is selected based on the parametric method. After 50 h of milling, the powders transformed into a solid solution having BCC structure with a minor fraction of undissolved Zr. The crystallite size (CS) of ∼ 7 nm reveals the nanocrystalline nature of the milled powder. The DSC thermograph displays the phase transformation of the milled powder near ∼ 821 °C. After sintering at 750 °C, the sample had only β (BCC) phase, however, after sintering at 850 and 950 °C, it appeared as both β and α (HCP) phases. Micro-hardness values of the sintered samples have been found to be in the range of 460 – 580 HV which is higher than that of similar biomaterials. This study reveals that Ti-Co0.35-Cr0.35-Nb-Zr HEA can be explored as a new class of biomaterials.

Effect of reinforcement types on the ball milling behavior and mechanical properties of 2024Al matrix composites

In this paper, 2024 Al matrix composites reinforced by nanocrystalline high-entropy alloy particles (NC-HEAp), SiC particles, and coarse-grained high-entropy alloy particles (CG-HEAp) were fabricated via powder metallurgy, and a comparative study of different reinforcements was deeply conducted. The results showed that reinforcement types significantly influenced the morphology of composite powders, and the grain size and interfacial condition of composites. After ball milling, irregular granular NC-HEA-Al and SiC–Al composite powders were produced while the CG-HEA-Al composite powders exhibited flake shapes, and particle size of NC-HEAp sharply decreased and was significantly smaller than the other two reinforcements. The Cu-rich diffusion layer, a high dislocation density, and a thin oxide layer were formed in the interfaces of NC-HEA-Al, SiC–Al, and CG-HEA-Al composites, respectively. The NC-HEA-Al composite possessed the highest strength due to the best effect of grain refinement, while the SiC–Al composite displayed better ductility attributed to higher work hardening rate after the yield stage than that of the NC-HEA-Al composite. The CG-HEA-Al composites showed the least attractive mechanical properties, related to a poor interface bonding and pre-existing cracks in CG-HEAp. Furthermore, the differences in strengthening mechanisms of the three composites were also discussed. This work provides guidelines for designing metal matrix composites fabricated by powder metallurgy.

Enhancing the oxidation resistance of nanocrystalline high-entropy AlCuCrFeMn alloys by the addition of tungsten

The isothermal oxidation behavior of multi-component high entropy alloys (HEAs), namely AlCuCrFeMn, AlCuCrFeMnW0.05, AlCuCrFeMnW0.1, and AlCuCrFeMnW0.5, was investigated and the behavior of the oxide layer was analyzed. All four HEAs were synthesized via mechanical alloying (MA) and consolidated by spark plasma sintering (SPS). The samples were oxidized in the air atmosphere at a temperature of 500 °C for 50 h. Based on the thermogravimetric result, the oxidation rate of the materials decreased with the increase of W content, and the values of parabolic constants were on a level similar to those observed in Ni–Al superalloys. However, higher content of W improves the continuity and internal position of the WO3 scale, which leads to increased oxidation resistance. Throughout the oxidation process, the composition of the phases of all materials changed significantly. The triple-thick oxide layer formed of Al2O3, Cr2O3, and WO3, developed in HEAs, has been carefully studied using the XPS technique.

Shock-induced dynamic response in single and nanocrystalline high-entropy alloy FeNiCrCoCu

The high-entropy alloys (HEAs) exhibit some unique atomic-scale plastic deformation mechanisms under extreme loading conditions (e.g., shock). Here, four samples are characterized and compared, including nanocrystalline and single-crystal samples in [001], [110], and [111] directions, in terms of their shock-induced dynamic plasticity and failure. Extensive molecular dynamics (MD) simulations show that the anisotropic crystal properties of FeNiCrCoCu HEA significantly affect the Hugoniot elastic limit and the corresponding two-zone elastic-plastic shock wave structures. Importantly, the plastic deformation mechanisms are also tuned by crystal anisotropy. The plastic deformation of the single-crystal sample along [001] direction is dominated by nanotwins and dislocation slip, while those of the other samples only exhibit dislocation slip. The nanotwins are formed by two adjacent stacking faults. In terms of the spallation, the critical shock intensities are different for the four samples. The shock speed threshold of spallation along the [001] and [111] directions is 0.7 km/s, while the [110] direction of 0.6 km/s. Nanocrystalline HEA shows a similar shock speed threshold with the single crystal along [110] direction. The simulation results of spall strength exhibit little discrepancy with the increase of shock velocity. In nanocrystalline HEA, the presence of grain boundaries leads to a low spall strength. During the spall evolution, the voids of single crystals nucleate in the amorphous region formed by the interaction of stacking faults. The spall defects of nanocrystalline samples display a heterogeneous nucleation mechanism at the grain boundaries.

Atomic insights into effects of temperature and grain diameter on the micro-deformation mechanism, mechanical properties and sluggish diffusion of nanocrystalline high-entropy alloys

In this work, the effects of temperature and grain diameter on the micro- deformation mechanism, tensile properties, and sluggish diffusion of nanocrystalline Al0.1CoCrFeNi HEAs during uniaxial tension have been studied by molecular dynamics (MD) simulations. The Hall-Petch (H-P) relation and inverse Hall-Petch relation still exist in nanocrystalline HEAs. At the case of grain diameter over a critical size (e.g., DG>14.77 nm for 300 K), the deformation mechanism of HEAs is that the accumulation of dislocations at grain boundaries leads to the increase of HEAs strength, which conforms the H-P relation. At the case of grain diameter below a critical size (e.g., DG<14.77 nm for 300 K), the migration of grain boundaries, amorphization of atoms as well as the rotation and merging of grains becomes the main deformation mechanism of HEAs, which weaken the strength of HEAs and conform the reverse H-P relation. The increase of temperature has a negative influence on the mechanical properties including Young’s modulus, yield strength and flow stress of HEAs. The critical grain size that undergoes the H-P and reverse H-P relation transformation increases with the increase of temperature. An increase in grain boundary thickness and the appearance of a large number of discrete amorphous atoms in the grains can be observed at high temperatures. The shear strain of atoms at grain boundaries is larger than that of atoms in other regions, and high temperature promotes the increase of atomic shear strains in HEA, especially at grain boundaries. The lengths of all types of dislocation lines and dislocation densities tend to decrease with increasing temperature, and Shockley dislocations always dominate all other dislocations at 300–1200 K. The MSD results show that nanocrystalline HEA have good stability at 300–1200 K, and small-grained HEAs have higher MSD value and diffusion coefficient than those of large-grained HEAs at 1200 K. Moreover, at higher temperature (2500 K), the MSD values of HEAs with DG= 7.4–23.45 nm all increases significantly, and the time-dependent curves basically overlap, indicating that the influence of grain boundaries on atomic diffusion can be ignored.

Ultrahard BCC-AlCoCrFeNi bulk nanocrystalline high-entropy alloy formed by nanoscale diffusion-induced phase transition

In the current work, the BCC-AlCoCrFeNi bulk nanocrystalline high-entropy alloy (nc-HEA) with ultra-high hardness was formed by nanoscale diffusion-induced phase transition in a nanocomposite. First, a dual-phase Al/CoCrFeNi nanocrystalline high-entropy alloy composite (nc-HEAC) was prepared by a laser source inert gas condensation equipment (laser-IGC). The as-prepared nc-HEAC is composed of well-mixed FCC-Al and FCC-CoCrFeNi nanocrystals. Then, the heat treatment was used to trigger the interdiffusion between Al and CoCrFeNi nanocrystals and form an FCC-AlCoCrFeNi phase. With the increase of the annealing temperature, element diffusion intensifies, and the AlCoCrFeNi phase undergoes a phase transition from FCC to BCC structure. Finally, the BCC-AlCoCrFeNi bulk nc-HEA with high Al content (up to 50 at.%) was obtained for the first time. Excitingly, the nc-HEAC (Al-40%) sample exhibits an unprecedented ultra-high hardness of 1124 HV after annealing at 500 °C for 1 h. We present a systematic investigation of the relationship between the microstructure evolution and mechanical properties during annealing, and the corresponding micro-mechanisms in different annealing stages are revealed. The enhanced nanoscale thermal diffusion-induced phase transition process dominates the mechanical performance evolution of the nc-HEACs, which opens a new pathway for the design of high-performance nanocrystalline alloy materials.

Role of electronic energy loss on defect production and interface stability: Comparison between ceramic materials and high-entropy alloys

High-entropy alloys (HEAs) and some complex alloys exhibit desirable properties and significant structural stability in harsh environments, including possible applications in advanced reactors. Energetic ion irradiation is often used as a surrogate for neutron irradiation; however, the impact of ion electronic energy deposition and dissipation is often neglected. Moreover, differences in recoil energy spectrum and density of cascade events on damage evolution must also be considered. In many chemically complex alloys, the mean free path of electrons is reduced significantly, thus their decreased thermal conductivity and slow dissipation of localized radiation energy can have noticeable effects on displacement cascade evolution that is greatly different from metals with high thermal conductivity. In this work, nanocrystalline HEAs of Ni20Fe20Co20Cr20Cu20 and nonequiatomic (NiFeCoCr)97Cu3, both having much lower room-temperature thermal conductivity than pure Ni or Fe, are chosen as model HEAs to reveal the role that electronic energy loss during ion irradiation has in complex alloys. The response of nanocrystalline HEAs is investigated under irradiation at room temperature using MeV Ni and Au ions that have different ratios of electronic energy to damage energy, which is the energy dissipated in displacing atoms. Different from previously reported amorphization of nanocrystalline SiC, experimental results on these HEAs show that, similar to the process in nanocrystalline oxide materials, both inelastic thermal spikes via electron–phonon coupling and elastic thermal spikes via collisions among atomic nuclei contribute to the overall grain growth. The growth follows a power law dependence with the total deposited ion energy, and the derived value of the power-exponent suggests that the irradiation-induced instability at and near grain boundaries leads to local rapid atomic rearrangements and consequently grain growth. The high power-exponent value can be attributed to the sluggish diffusion and delayed defect evolution arising from the chemical complexity intrinsic to HEAs. This work calls attention to quantified fundamental understanding of radiation damage processes beyond that of simplified displacement events, especially in simulating neutron environments.

Cyclic Oxidation Properties of the Nanocrystalline AlCrFeCoNi High-Entropy Alloy Coatings Applied by the Atmospheric Plasma Spraying Technique

Microcrystalline and nanocrystalline AlCrFeCoNi high-entropy alloy (HEA) coatings were applied on Inconel 718 superalloy using the atmospheric plasma spraying (APS) process. The high-temperature oxidation behavior of the microcrystalline and nanocrystalline AlCrFeCoNi HEA-coated superalloy was examined at 1100 °C under the air atmosphere for 50 cycles under cyclic heating and cooling (1 h for each cycle). The oxidation kinetics of both nanocrystalline- and microcrystalline-coated superalloys were accordingly analyzed by weight change measurements. We noted that the uncoated and coated samples followed the parabolic rate law of the oxidation. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDS), elemental mapping and X-ray photoelectron spectroscopy (XPS) were used to analyze the oxidized coated and uncoated samples. In the HEA-coated superalloy, Fe, Ni, Co and Al were oxidized in the inter-splat region, whereas the splats, which consisted mainly of Ni and Cr, remained unoxidized. Due to the formation of compact and adhesive thin NiO, CoO oxides and spinels together with the Al2O3 oxide scale on the surface of the coating during oxidation, the developed nanocrystalline HEA coating showed better oxidation resistance compared with the microcrystalline HEA coating.

Shock-induced spallation in a nanocrystalline high-entropy alloy: An atomistic study

High-entropy alloys are attracting an increasing interest due to their promising mechanical properties. However, their high-pressure properties are not fully understood. We study shock-induced spallation in a nanocrystalline high-entropy alloy using various grain sizes. Our results show that the spall strengths for the nanocrystals are significantly reduced in comparison to single crystals. In contrast to previous results on single crystals, we observe a large number of stacking faults, twins, and dislocations during the shock, which persist even during the release of the shock wave. This behavior is in good agreement with recent experiments of shock loading via high power lasers where pronounced nanotwinning has been observed in the recovered samples.

The Impact of Surface Scratches on the Corrosion Behavior of Nanocrystalline High Entropy Alloy Coatings: Electrochemical Experiments and First-Principles Study

The Impact of Surface Scratches on the Corrosion Behavior of Nanocrystalline High Entropy Alloy Coatings: Electrochemical Experiments and First-Principles Study

Electrodeposited nanocrystalline medium-entropy alloys – An effective strategy of producing stronger and more stable nanomaterials

For decades, enhancing both strength and thermal stability in nanocrystalline materials for structural applications has been a significant challenge. Recently, entropy-based stabilization strategies for nanostructured materials have gained traction in the high-entropy alloy (HEA) community, however, such studies typically focus on synthesis techniques that require high energy input, such as severe-plastic-deformation or sputtering-based techniques. By contrast, electrodeposition offers itself as a low-energy and low-cost method of producing nanocrystalline materials, which has seen infrequent investigation in the HEA design space. Here we identify two nanocrystalline medium-entropy alloys (MEAs), NiFeCo (grain size, D = 13–360 nm) and NiFeCr (D ~ 1 nm), to serve as a baseline for the further development of higher-order quaternary and quinary systems. These alloys show enhanced thermal stability when compared to pure metal and binary alloy electrodeposits, and even nanocrystalline CoCrFeNiMn (made by high-pressure torsion) in the case of NiFeCr. Hardness values ranged from 3.4-5.5 GPa in NiFeCo and 4.6–8.5 GPa in NiFeCr, which are comparable with nanocrystalline HEAs made by other techniques. This study provides a framework for the development of nanocrystalline HEAs by electrodeposition, whose further development has the potential to accelerate the commercialization of HEAs, which currently have limited use despite their widespread acclaim in the materials community.

Investigation of shape memory characteristics and production of HfZrTiFeMnSi high entropy alloy by mechanical alloying method

High entropy alloy (HEA) with shape memory effect (SME) has been the subject of great interest for the past few decades. However, with the increased demands for new materials for high thermal applications, the research activities on the multi elemental high entropy shape memory alloys (HESMA) have been increased by many folds recently. The nano crystalline HEA powder with shape memory effect developed in this study, HfZrTiFeMnSi, was produced by mechanical alloying (MA) for the first time. In this method equiatomic ratio of Hf, Zr, Ti, Fe, Mn, and Si were mixed together and milled by MA process for 100 h. The powder formed was of amorphous in nature. Elemental mapping of the powder from SEM-EDS revealed homogeneity of the alloying elements confirming successful fabrication of HfZrTiFeMnSi HEA powder. The DSC studies from ambient to 500 °C of the annealed alloy powders showed reversible austenitic to martensitic (A↔M) transformations. The A↔M transformation hysteresis seemed to vary with the milling time and annealing temperature. The enthalpy values, ΔH, for the transformation were calculated from the DSC plots using tangent method for peak area calculation. Regardless of the annealing temperature, the thermal analysis revealed that the ΔH, equilibrium temperature (T0), and crystallization temperature values decreased with the increasing milling time.

Nanostructured high-entropy alloys by mechanical alloying: A review of principles and magnetic properties

The principles and magnetic properties of nanostructured high-entropy alloys (HEAs) processed by mechanical alloying are overviewed. Firstly, the general concepts of HEAs (multi-principal element alloys with ≥5 elements) and phase formation rules are briefly reviewed. Subsequently, the processing of nanocrystalline and amorphous HEAs by mechanical alloying and the effect of high-energy ball milling parameters are summarized. Finally, the magnetic properties of nanostructured HEAs are critically discussed to infer some general rules. In summary, a higher content of ferromagnetic elements (e.g. Fe, Co, and Ni) normally results in a higher saturation magnetization. The as-milled products with solid solution phases show better soft-magnetic properties compared to the fully amorphous phases, and increasing the amount of the amorphous phase decreases the saturation magnetization. The magnetic properties are also influenced by processing (such as sintering) and thermal history through the alteration of phases and crystallite size.

An advancement in the synthesis of unique soft magnetic CoCuFeNiZn high entropy alloy thin films

Discovery of advanced soft-magnetic high entropy alloy (HEA) thin films are highly pursued to obtain unidentified functional materials. The figure of merit in current nanocrystalline HEA thin films relies in integration of a simple single-step electrochemical approach with a complex HEA system containing multiple elements with dissimilar crystal structures and large variation of melting points. A new family of Cobalt–Copper–Iron–Nickel–Zinc (Co–Cu–Fe–Ni–Zn) HEA thin films are prepared through pulse electrodeposition in aqueous medium, hosts nanocrystalline features in the range of ~ 5–20 nm having FCC and BCC dual phases. The fabricated Co–Cu–Fe–Ni–Zn HEA thin films exhibited high saturation magnetization value of ~ 82 emu/g, relatively low coercivity value of 19.5 Oe and remanent magnetization of 1.17%. Irrespective of the alloying of diamagnetic Zn and Cu with ferromagnetic Fe, Co, Ni elements, the HEA thin film has resulted in relatively high saturation magnetization which can provide useful insights for its potential unexplored applications.

Effects of microstructure and temperature on the mechanical properties of nanocrystalline CoCrFeMnNi high entropy alloy under nanoscratching using molecular dynamics simulation

In this study, molecular dynamics is used to examine mechanical properties and microstructure evolution of nanocrystalline high-entropy alloy (CoCrFeMnNi) under nanoscratching load. Special attentions are paid to the effects of crystal structure, temperature, grain size and twin boundary spacing on the deformation mechanisms and microstructure evolution. The P-h curves show that the maximum indentation force is in reduced order with single-crystal, nanotwin polycrystalline and polycrystalline structures. Specifically, for the single-crystal structure, the amorphization caused by the increment of temperature hinders the movements of dislocations and stacking faults. For the polycrystalline and nanotwin polycrystalline structures, the inverse Hall–Petch relation is observed due to that the interaction between the dislocations and grain boundary (GB) / twin boundary (TB). For the nanotwin polycrystalline structure, the migration of twin boundary is observed during the process of nanoindentation. Furthermore, Hirth and Lomer-Cottrell dislocation locks, secondary twins and FCC→HCP phase transformation are also found in simulations.

Stacking fault and transformation-induced plasticity in nanocrystalline high-entropy alloys

In this work, the plastic deformation in a model nanocrystalline high entropy alloy (HEA), CoNiCrFeMn, is studied by using molecular dynamics simulations. It is found that the plastic deformation of nanocrystalline CoNiCrFeMn HEAs is dominated by a partially reversible face-centered cubic (FCC) to hexagonal close-packed (HCP) transformation mediated by stacking faults and partial dislocations, which is dramatically different from the full dislocation and deformation twinning-dominated plasticity in conventional FCC metals. This mechanism is strongly associated with the metastable nature of CoNiCrFeMn. Furthermore, although the transformed HCP structures can hinder the migration of the subsequent partial dislocations, they can penetrate each other to form a complicated stacking fault network, which is consistent with the recent experimental observations. Nevertheless, the nanocrystalline CoNiCrFeMn HEAs still show the conventional Hall–Petch breakdown when the grain sizes are reduced below a critical value. It is hoped that this study provides an atomistic insight into the plasticity of metastable HEAs and sheds some light on the design of novel HEAs for ultrahigh strength and plasticity.

Nanocrystalline equiatomic CoCrFeNi alloy thin films: Are they single phase fcc?

The bulk quaternary equiatomic CoCrFeNi alloy is studied extensively in literature. Under experimental conditions, it shows a single-phase fcc structure and its physical and mechanical properties are similar to those of the quinary equiatomic CoCrFeMnNi alloy. Many studies in literature have focused on the mechanical properties of bulk nanocrystalline high entropy alloys or compositionally complex alloys, and their microstructure evolution upon annealing. The thin film processing route offers an excellent alternative to form nanocrystalline alloys. Due to the high nucleation rate and high density of defects in thin films synthesized by sputtering, the kinetics of microstructure evolution is often accelerated compared to those taking place in the bulk. Here, thin films are used to study the phase evolution in nanocrystalline CoCrFeNi deposited on Si/SiO2 and c-sapphire substrates by magnetron co-sputtering from elemental sources. The phases and microstructure of the films are discussed in comparison to the bulk alloy. The main conclusion is that second phases can form even at room temperature provided there are sufficient nucleation sites.

Synthesis, microstructural investigation and compaction behavior of Al0.3CrFeNiCo0.3Si0.4 nanocrystalline high entropy alloy

This research article focused on developing Al0.3CrFeNiCo0.3Si0.4 nanocrystalline high-entropy alloy (HEA) by mechanical alloying. The initial powders mixture was ball milled for 1 hr (HEA-1 h), 5 hr (HEA-5 h), 15 hr (HEA-15 h) and 25 hr (HEA-25 h) at ball to powder mass ratio (BPR) of 15:1 and a speed of 300 rpm. The mechanical alloying time was varied from 1 to 25 hr to ensure the nanocrystalline nature and attainment of steady state in HEA powders. The structure of the developed HEAs was characterized by means of X-ray diffraction (XRD), Laser particle size analyzer (LPSA), and various electron microscopes (TEM and FEGSEM with EDS). HEA-25hr sample exhibited the crystallite size of 13.8 nm with lattice strain of 0.67% obtained from XRD which matched the result by TEM. The formation of a solid solution (SS) with a uniform elemental dispersion was observed with a major BCC stable structure and a minor FCC structure in HEA-25 h sample. The HEA-25 h sample revealed an average particle size of 386.2 nm (89.8% peak intensity) with Polydispersity Index (PDI) value of 0.364 which confirmed the uniform distribution of particles over a narrow range of particle size. The synthesized powders were consolidated to green compacts with a loading rate of 1 mm/min at different compaction pressures (25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, and 1100 MPa) for examining the powder particles packing. Several compaction models (both linear and non-linear) were discussed to establish the density-pressure relationship of developed HEAs. The results revealed that the milling time has influenced the relative density. HEA-1 h sample was exhibited the relative density of 0.76 whereas HEA-25 h sample was produced the relative density of 0.6 indicating more strength and more amount of strain hardening occurs in MAed HEA-25 sample in addition to the entropy effect for the same composition.

Synthesis and characterization of nanocrystalline high entropy alloy powder

In the present study, non-equiatomic nanocrystalline high entropy alloys (Fe, Al, Cr, Mn, and Ni) powder was synthesized using a high-energy planetary ball mill. During milling, a small amount of powder was collected after a different interval of milling time (2 h, 5 h, 10 h, and 20 h). The milled powders after different milling times were characterized using X-ray diffraction (XRD), and Differential Scanning Calorimetry (DSC). The crystallite size of the milled powder was calculated by analyzing XRD results using the Williamson-Hall method. XRD analysis exhibits that the crystallite size of 20 h milled powder particles is in the nano regime. Besides, lattice parameter, micro-strain and dislocation density of the milled powders were calculated. The melting point of milled powder was analyzed using DSC. The characterization of milled powder suggests the successful formation of nanocrystalline high entropy alloys powder using high-energy ball milling.

Microstructure, mechanical properties and machinability of particulate reinforced Al matrix composites: a comparative study between SiC particles and high-entropy alloy particles

In this study, 2024Al matrix composites reinforced by SiC particles (SiC-2024Al) and nanocrystalline high-entropy alloy particles (HEA-2024Al) fabricated by powder metallurgy were systematically compared for the first time. There is a significant difference in microstructure and mechanical properties as well as machinability between two kinds of composites. In term of microstructure, when the volume fraction of reinforcements was 10%, both SiC-2024Al and HEA-2024Al composites showed a homogeneous particle distribution in the matrix. With the increase of reinforcement content, HEA-2024Al composites presented denser microstructure than that of SiC-2024Al composites. The composites with 10, 20 and 30 vol.% HEA reinforcements all showed better plasticity than that of the SiC-2024Al composites with same volume fraction of reinforcements, which was related with better particle distribution and interface bonding. However, the strength showed the opposite tendency in the two kinds of composites. Selecting 10SiC-2024Al and 10HEA-2024Al composites as examples to explore the difference in the yield strength of two kinds of composites, it is ascribed to the dislocation punched zones around interface between the Al matrix and reinforcements, which was analyzed in detail by a combination of calculation, nanoindentation tests and finite element analysis. Additionally, HEA-2024Al composites showed better machinability than those of SiC-2024Al composites. This work provides insight into the application of particulate reinforced Al matrix composites.