Reinforced Aluminum Matrix Composites Research Articles

Microstructure and thermal conductivity of short carbon fiber/Al composites with nickel-coated carbon fibers consolidated by vacuum hot pressing for electronic packaging applications

Short carbon fiber reinforced aluminum matrix composites exhibit suitable thermal conductivity and desirable coefficient of thermal expansion for electronic packaging applications. The interfacial bonding characteristics between carbon fibers and aluminum matrix play a crucial role in determining the performance of the composites. In the present study, the surface modification of carbon fibers and optimization of fabrication processing parameters were used to ameliorate the interface bonding and improve the properties of carbon fiber/Al composites. The electroless plating method was employed to deposit a nickel coating on the surface of carbon fibers. Aluminum matrix composites reinforced with 20∼50 vol.% uncoated or nickel-coated carbon fibers were fabricated by vacuum hot pressing technique. The microstructures, interface structures, relative density and thermal conductivity of the composites were systematically investigated. The results indicated that carbon fiber/Al composites with relatively high density of 98.9% and acceptable thermal conductivity of 218.1 W·m−1 K−1, as potential candidates for electronic packaging applications, were successfully fabricated. Through the application of nickel coating, the interfacial thermal resistance was effectively reduced by one order of magnitude derived from the experimental calculations using Maxwell-Garnett effective medium approach as a result of improved interface bonding.

High-strength aluminum matrix composites with strong bonding interfaces via in-situ amorphous alumina and plainification strategy

Silicon carbide particle (SiCp) reinforced aluminum matrix composites have potential applications for components under severe service conditions. However, their performance is commonly limited by challenges such as insufficient interfacial bonding strength, agglomeration and brittle interfacial reaction products. In this paper, the ultra-fine grained aluminum and in-situ formed amorphous alumina were fabricated, and the as-formed powder metallurgy SiCp/Al composites achieved excellent properties, with a high yield strength of 471 MPa and an ultimate tensile strength of 505 MPa, respectively. We systematically investigated the structures of the amorphous alumina, which bonds the SiCp and matrix together, improving the interfacial bonding strength and simultaneously suppressing the interfacial reactions. Notably, the proposed fabrication method is suitable for economic production of large-scale components and applicable for aluminum matrix composites with other types of reinforcements.

Tribological characterization of high entropy alloy particles reinforced aluminum matrix composites at room and cryogenic temperatures

Tribological characterization of high entropy alloy particles reinforced aluminum matrix composites at room and cryogenic temperatures

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Mechanical property and fracture characteristics of carbon fiber reinforced aluminum matrix composites prepared by friction stir welding

Interfacial structure and strengthening mechanisms of NiO-coated graphene reinforced aluminum matrix composites

Interfacial structure and strengthening mechanisms of NiO-coated graphene reinforced aluminum matrix composites

Experimental investigation and mathematical modelling of dry sliding wear of nitinol reinforced aluminium matrix composite using machine learning

Dry sliding wear is a complex phenomenon, an understanding of which needs careful experimentation and observation of the wear event. The present study focuses on the dry sliding wear analysis of the nitinol particulate-reinforced Al5083 matrix composite fabricated using a vacuum-assisted stir casting route. Nitinol alloys have excellent mechanical, thermo-mechanic and tribological performance along with the unique feature of shape recovery and superelasticity in the austenitic phase. The effect of varying wear control parameters, load (5–20 N), sliding distance (0–3000), sliding speed (150–600 RPM), humidity (20% – 80%) and temperature (25–100°C) on the wear resistance of the fabricated composites were exhaustively examined. Steady-state, as well as Taguchi-based experimentation, were performed to investigate the wear phenomenon in the fabricated composite using a pin-on-disc tribometer. Modified Archard equation with power exponent was utilized to develop four new wear equations, which were both trained and tested using a machine learning algorithm. The results depict that among all four models, the DSW Model-4 has provided the best fit between the actual and the predicted wear volume with a coefficient of determination value of 0.9722. An infrared thermal imager was used to observe temperature variation during the wear test. Scanning electron microscopy (SEM) and a profilometer were used to carefully examine the worn surface.

Effect of MnO2 addition on the microstructure and properties of high-volume fraction SiCp/Al composites fabricated by pressureless melt infiltration

High-volume fraction silicon carbide particles reinforced aluminum matrix composites (SiCp/Al) with low coefficient of thermal expansion (CTE) and high thermal conductivity (TC) were fabricated by infiltrating Al-Si-Mg alloy in air atmosphere without pressure into porous SiC preforms doped with different manganese dioxide (MnO2) content in order to investigate the effectiveness of MnO2 as infiltration aid. The effect of MnO2 on the infiltration time, microstructure and thermo-mechanical properties of the composite materials were studied. The volume ratio of SiC to MnO2 was set at 100:0, 100:5, 100:10 & 100:15 respectively. Obtained results showed the effectiveness of MnO2 as infiltration aid as the infiltration time was significantly reduced, the wetting between SiC and Al and interfacial bonding strength were considerably improved with the addition of MnO2. Harmful and brittle aluminum carbide (Al4C3) was not detected at the interface of the Al alloy and SiC ceramic phase. The composites with 100:15 MnO2 and 100:10 MnO2 content were found to have less incubation period and infiltration time. Optimum dispersion of SiC particles in the Al alloy and better properties were obtained with 100:10 MnO2 content composite samples. The properties are; a coefficient of thermal expansion (RT to 473 K) of 9.3 × 10−6 K−1, a thermal conductivity of 200.5 W/(mK), a hardness of 145.2 HBW and a bending strength of 338.0 MPa.

Micro milling mechanism and tool wear of Unidirectional HfZrTiTaNbCu0.2 fiber reinforced aluminum matrix composites

This study delves into the micro milling and tool wear mechanisms of 2A97 aluminum matrix composites reinforced with HfZrTiTaNbCu0.2 fibers. Finite element analysis models the fibers as uniformly distributed cylindrical entities within the matrix, applying various material constitutive laws, failure, and evolution criteria to simulate milling at three specific angles (45°, 90°, 135°). The research examines the effects of milling parameters, fiber orientations, and tool coating thickness on cutting forces, temperatures, surface roughness, and tool wear. Key findings include: These forces escalate with both cutting speed and depth of cut. Notably, at a feed rate of 68 μm/z, the cutting force is 1.5 times higher compared to 58 μm/z.An increase in milling parameters leads to higher cutting temperatures. Differences of 12 °C and 10 °C were noted at varying depths of cut (10–25 μm) and cutting speeds (1000–1200 mm/s), respectively. As the fiber angle increases, cutting forces first decrease and then rise, with fibers oriented at 90° experiencing only 53 % of the force compared to those at 135°. Similarly, cutting temperatures follow this trend, with a 26 °C difference between 45° and 90° fibers. This factor is positively correlated with depth of cut and fiber angle. Surface roughness at a 55 μm depth is 4.3 times that at 10 μm, and 135° fibers show 2.7 times the roughness of 45° fibers. However, within feed rates of 48–58 μm/z and cutting speeds of 800–1200 mm/s, there is a notable decrease in surface roughness. Variations in cutting parameters, fiber orientations, and tool coating thickness significantly influence peak tool stress. Stress concentration at the central groove tends to reduce tool wear, whereas stress concentration at the peripheral edge or strain concentration at the bottom edge exacerbates it.

Investigation of the Thermophysical Simulation and Material Removal Mechanism of the High-Volume-Fraction SiCp/Al Composite in Wire Electrical Discharge Machining.

SiC particle reinforced aluminum matrix composites (SiCp/Al) are widely used in aviation, weaponry, and automobiles because of their excellent service performance. Wire electrical discharge machining (WEDM) regardless of workpiece hardness has become an alternative method for processing SiCp/Al composites. In this paper, the temperature distribution and the discharge crater size of the SiCp/Al composite are simulated by a thermophysical model during a single-pulse discharge process (SPDP) based on the random distribution of SiC particles. The material removal mechanism of the SiCp/Al composite during the multi-pulse discharge process (MPDP) is revealed, and the surface roughness (Ra) of the SiCp/Al composite is predicted during the MPDP. The thermophysical model simulation results during the MPDP and experimental characterization data indicate that the removal mechanism of SiCp/Al composite material consists of the melting and vaporization of the aluminum matrix, as well as the heat decomposition and shedding of silicon carbide particles. Pulse-on time (Ton), pulse-off time (Toff), and servo voltage (SV) have a great influence on surface roughness. The Ra increases with an increase in Ton and SV, but decreases slightly with an increase in Toff. Moreover, compared with experimental data, the relative error of Ra calculated from the thermophysical model is 0.47-7.54%. This means that the developed thermophysical model has a good application and promotion value for the WEDM of metal matrix composite material.

Nanocrystalline NiTiB reinforced aluminum matrix composites: Synthesis, structural, mechanical and corrosion properties

In this study, aluminum composites were developed using a powder metallurgy route by incorporating varying amounts of nanocrystalline NiTiB into the Al2024 alloy. The effects of nanocrystalline NiTiB on the structural, morphological, corrosion, and mechanical properties of the aluminum composites were thoroughly investigated. The results showed that the base alloy and composites with 2% and 4% NiTiB exhibited the highest relative density. The composite with 4% NiTiB achieved the maximum hardness of 87.4 HV. Additionally, the inclusion of nanocrystalline NiTiB significantly improved the compressive strength, corrosion resistance, and wear resistance of the composites. Specifically, the compressive strength increased by approximately 2% with 2% NiTiB and by around 13% with 12% NiTiB. Corrosion resistance was highest in the composite with 4% NiTiB, as confirmed by electrochemical impedance spectroscopy. In the wear-loss study, the wear loss of the composites was found to be reduced by 244% and 457% for those reinforced with 2% and 12% NiTiB, respectively. These findings underscore the potential of nanocrystalline NiTiB to enhance the performance of Al2024 composites in applications demanding superior corrosion resistance, mechanical strength, and wear resistance.

Preparation and tribological behavior of Cr3C2 particles reinforced Al matrix composite

In this study, Cr3C2 particle reinforced aluminum matrix composites were fabricated by ultrasonic agitation casting method. Microstructure, mechanical properties, and tribological properties of pure aluminum and Cr3C2p/Al composites were researched systematically. Scanning electron microscopy and 3D laser scanning confocal microscope were used to study the influence of different loads (10, 20, 30, and 40 N) and Cr3C2 contents (1.0, 2.0, 3.0, and 4.0 wt %) on the tribological behaviors of the composites. The results showed that 2.0 wt % Cr3C2p/Al composites exhibited the best mechanical properties and wear resistance. The average volume wear rate was about 48 % lower than that of the matrix material. The wear mechanism of the composites changed from adhesion wear to abrasive wear and fatigue wear with the addition of Cr3C2 particles. The tribological properties of 2.0 wt % Cr3C2p/Al composites under the load of 30 N were the best. The average volume wear rate was the smallest, which was about 24 % lower than that of 10 N load. The improvement of the tribological behavior of the composite was attributed to the refinement of microstructure and improvement of the mechanical properties.

Characterization of different size reinforcement effects on microstructural failure mechanism in carbon nanotube-reinforced aluminum composites

In this study, we investigated the effect of reinforcement sizes on the tensile strength and ductility of carbon nanotube (CNT)-reinforced aluminum matrix composites fabricated through ball milling, followed by hot extrusion of a powder encapsulated in an aluminum container. We analyzed the microstructural properties of the samples, including the aluminum grain size, its spatial variation with the alignment of CNT, and CNT length. Nanoindentation test results revealed the spatial variation of hardness and Young’s modulus of composites with small-diameter CNTs, indicating local Al4C3 formation and interlock structure resulting from dislocation accumulation during the fabrication process. This explains dimples of different sizes observed on the fracture surfaces of the samples and the occurrence of CNT pullout. Furthermore, we proposed the failure mechanism of the composites under tensile strain and calculated the failure strain using the Whitehouse–Clyne model. The calculated failure strain agrees well with the experimental values. The high ductility of the composites is attributed to the large grain fracture and rotation of neighboring grains due to the constraint imposed by CNTs.

Microstructure evolution and mechanical properties of selective laser melting fabricated hybrid particle reinforced AlSi10Mg composites

(SiC+TiB2)/AlSi10Mg composite powders with 5 wt% micro-SiC particles and 1.5 wt% nano-TiB2 particles were prepared by high energy ball milling, and hybrid particle reinforced aluminum matrix composites (AMCs) were fabricated by SLM. This study systematically investigated the effects of SiC and TiB2 particles on the phase composition, microstructure evolution, grain crystallization, and mechanical properties. The machanisms of potential strengthening and fracture mechanisms were revealed. The tribological behaviors of the hybrid particle reinforced AlSi10Mg composites under different friction conditions were explored as well. The results show that the 1.5 wt% nano-TiB2 particles provided sufficient nucleation sites for grain growth, completely transforming from coarse columnar to fined equiaxed grains. The average grain size decreases from 7.98 μm to 3.34 μm, and the texture is significantly weakened, which is beneficial to the homogenization of the microstructure, thereby improving the mechanical properties of the SiC/AlSi10Mg composites. The (SiC+TiB2)/AlSi10Mg composites showed a high ultimate tensile strength (∼ 489.1 MP), hardness (172.2 HV) and elongation of 8.2 %. The enhancement of mechanical properties was attributed to Orowan strengthening, fine grain strengthening, and load-bearing strengthening. Due to the Si precipitates and fine microstructure, a low wear rate of 0.50 × 10−5 g/m was obtained, 10.7 % lower than that of SLM formed SiC/AlSi10Mg composites. The friction process is affected by abrasive wear, adhesive wear and delamination wear. It is aspired that the current approach can provide guidance for the design of new alloy systems with excellent performance.

Tribological performance and mechanism of the titanium fiber-SiC whisker hybrid reinforced aluminum matrix composites prepared by pressure infiltration

In this contribution, a Ti-6Al-4V fiber (Tif) and SiCw (SiCw) hybrid reinforced 5056 Al composites (Tif + SiCw/5056 Al) were fabricated, and the effects of SiC whisker contents on the microstructure, mechanical properties, and wear resistance were investigated. The mechanical properties and the hardness of the composites increased first and then decreased with the increase of SiCw contents. The optimal ratio of SiCw to titanium fibers is 3 wt%. The flexural strength of the optimal composites reached 533 MPa, and the fracture toughness reached 29.1 MPa m1/2. Under a load of 40 N, compared with the Tif/5056 Al composites sample, the wear rate of the optimal composites sample decreased by 80.7 %. The uniformly dispersed SiC whiskers promote the formation of a mechanical mixing layer (MML) on the friction surface; the wear mechanism mainly involves abrasive wear and adhesive wear.

Mechanical Effects of Carbon Nanotubes-Graphene Reinforced Aluminium Matrix Composites

In this paper, MWCNTs-GN hybrid reinforcement was prepared by wet ball milling process. The MWCNTs-GN/Al composites were prepared by high-energy ball milling and vacuum hot-pressure sintering. The MWCNTs-GN hybrid reinforcements and MWCNTs-GN/Al composites were characterised by SEM and TEM, and the synergistic effects of carbon nanotubes and graphene on the mechanical properties of the aluminium matrix composites were investigated by hardness and friction wear tests. The results show that the 0.5 wt.% MWCNTs-GN/Al composite has the best mechanical properties, with a hardness of 116.3 MPa which is 33.9% higher than that of pure aluminium, and the frictional properties of the MWCNTs-GN reinforced aluminium matrix composites have a lower coefficient of friction than that of pure aluminium. After the addition of more than 5 wt.% of the composite reinforcing phase, the wear rate increased slightly due to the reduced densities of the MWCNTs-GN/Al composites.

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.

Abrasive wear behavior of functionally graded Al3Ti reinforced aluminum matrix composite

Abrasive wear behavior of functionally graded Al3Ti reinforced aluminum matrix composite

Microstructure and performance of carbon fiber reinforced aluminum matrix composites with molybdenum carbide coating on carbon fibers

In this work, a molybdenum carbide coating on the surface of short carbon fibers prepared using molten salt method was proposed to ameliorate the interfacial bonding and improve the performance of carbon fiber/Al composites. The carbon fiber/Al composites were produced using vacuum hot pressing. The characteristics of molybdenum carbide coating were analyzed. Besides, the microstructures, bending strength and thermal properties of the carbon fiber/Al composites were explored. Furthermore, the interfacial thermal resistance of the composites was investigated in relation to theoretical evaluations derived from the combined Maxwell-Garnett effective medium approach and acoustic mismatch model schemes. The results indicated that a homogeneous Mo2C coating with a thickness of 0.5 μm was obtained by proper molar ratio of carbon fibers, MoO3 and chloride salts mixture and heated at 1000 °C for 60 min. The Mo2C coating greatly enhanced the bond between the aluminum matrix and carbon fiber, leading to improvements in the densification behavior and bending strength of the coated composites. The enhanced thermal properties including improved thermal conductivity and reduced coefficient of thermal expansion (CTE) were also achieved by the Mo2C coating. The in-plane thermal conductivity of 60 vol.% Mo2C-coated carbon fiber/Al composite was 221 W·m−1·K−1 enhanced by 92% compared to that of uncoated composite and the CTE was 6.0 × 10–6 K−1 which was suitable for electronic packaging materials.