Reinforced Aluminum Composites Research Articles

Micromechanical modeling of longitudinal compression behavior and failure mechanism of unidirectional carbon fiber reinforced aluminum composites involving initial fiber misalignment

AbstractA micromechanical model with realistic initial fiber misalignment (IFM) was developed to simulate the longitudinal compression behavior of unidirectional carbon fiber/aluminum composites. The matrix and fiber were modeled using ductile damage law and brittle fracture model, respectively. The interfacial properties were firstly determined by the single‐fiber push‐out and transverse tensile tests, and the cohesive zone model was adopted to capture the interfacial behavior. The calculated compressive response curve is in alignment with the experimental data. Compression failure can be attributed to fiber kinking, possibly triggered by the matrix shear damage. The increase of IFM angle makes the failure mode being transformed from fiber crushing to fiber kinking, along with a significant decrease in compressive strength. With the fiber content increasing, the compressive strength increases first and then decreases, while the compressive modulus increases monotonically. Increasing interfacial strength significantly improves the compressive strength, but this is limited by the matrix properties.

Plastic deformation and fracture of AlMg6/CNT composite: A damage evolution model coupled with a dislocation-based deformation model

Understanding the plastic deformation and fracture behavior of Carbon nanotube (CNT)-reinforced aluminum composites is crucial for determining the factors controlling their strength and ductility. This article presents a novel approach by proposing a coupled micromechanical dislocation-based constitutive model combined with the Gurson-Tvergaard-Needleman (GTN) damage evolution model. The objective of this research is to accurately predict the load-displacement behavior of an AlMg6/CNT composite, which is manufactured through accumulative roll bonding (ARB), from yield to fracture. The study investigates the correlations between the number of ARB passes, which affects the dislocation density of the matrix, and the distribution of CNTs in the composite, with the GTN parameters. The analysis reveals that the volume fraction of void nucleating particles (fN) is a critical parameter influencing the ductility of the composite ductility. Initially, due to CNT agglomeration, they act as nucleation sites for damage, resulting in an increase in fN and a decrease in ductility. However, as the number of ARB passes increases, leading to a homogeneous CNT distribution, fN decreases, and CNTs contribute to improved strength and ductility of the composite. The proposed model accurately predicts the load-displacement curve of the composite during uniaxial tensile testing, taking into account the effect of ARB passes. The research findings provide insights for future extensions of the GTN model, aimed at enhancing its theoretical framework and applicability in the field.

Effect of Short Heat Treatments on the Microstructural Evolution and Hardness of Thixoformed Graphene Reinforced Aluminium Composites

Aluminium metal matrix composites are increasingly being used in numerous industries due to their lightweight nature and high strength. The incorporation of graphene into aluminium metal matrix composites has garnered significant interest owing to graphene's capacity to enhance numerous properties concurrently. Hence, this study aimed to fabricate a 0.3 wt.% graphene nanoplatelets reinforced A356 alloy (GNP-A356) composite through stir casting followed by thixoforming and short T6 heat treatment processes. It also evaluated the microstructure and mechanical properties of GNP-A356 after the thixoforming process and short T6 heat treatment. The microstructure of alloy and composite was confirmed by optical microstructure, field emission scanning electron microscopy images, and X-ray diffraction. Microstructure investigations demonstrate the impact of the stirring process on the structural transformation of the 𝛼-Al phase from the dendritic into a rosette-like and globular-like structure. The result also indicated that there was a transformation of eutectic silicon from the shape of a needle-like to spheroid structure after a short heat treatment, showing the efficiency of T6 heat treatment with a shorter time of solution treatment and ageing. Moreover, the increase in relative density and addition of reinforcement led to a significant increment in hardness. The result shows the hardness improved by 35.77% and 77.8% for as-cast and heat-treated composites, respectively, compared to A356 alloy.

Numerical Study of Reinforced Aluminum Composites for Steering Knuckles in Last-Mile Electric Vehicles

The steering knuckle is a critical component of the suspension and steering drive systems of electric vehicles. The electrification of last-mile vehicles presents a challenge in terms of cost, driving range and compensation of battery weight. This work presents a numerical methodology to evaluate 60XX series aluminum metal matrix composites (AMMCs) with reinforcement ceramic particles for steering knuckle components in medium heavy-duty last-mile cargo vehicles. The use of AMMCs provides lightweight knuckles with sufficient strength, stiffness and safety conditions for electrical vehicle cargo configurations. The numerical study includes three aluminum alloys, two AMMC alloys and an Al 6061-T6 alloy as reference materials. The medium-duty heavy vehicle class < 12 t, such as electrical vehicle cargo configurations, is considered for the numerical study (class 1–4). The maximum von Mises stress for class 4 AMMC alloys exceeds 350 MPa, limited by fracture toughness. The weight reduction is about 65% when compared with commercial cast iron. Moreover, Al 6061-T6 alloys exhibit stress values surpassing 300 MPa, constraining their suitability for heavier vehicles. The study proposes assessing the feasibility of implementing AMMC alloys in critical components like steering knuckles and suggests solutions to enhance conventional vehicle suspension systems and overcome associated challenges. It aims to serve as a lightweight design guide, offering insights into stress variations with differing load conditions across various cargo vehicles.

Fabrication of wear resistant nanocomposite and its mechanical properties: A step towards sustainability

AbstractNowadays, particulate reinforced aluminium composites are appealing structural materials for numerous applications, such as automotive and aerospace, due to their low weight and high specific strength. Nanocomposite morphology and interfacial properties may alter when nano sized particles are reinforced with an aluminium matrix. The addition of nano reinforcement of aluminium oxide particle improve the mechanical strength of base alloy and a further improvement in mechanical properties may be enhanced by grain refinement processed under multi axial forging technique. The present study demonstrates the synthesis of wear resistant nanocomposite. It also investigates the effect of multi axial forging on microstructure, mechanical properties and wear behaviour of aluminium based nanocomposite. Optical microscopy and electron backscatter diffraction techniques were used for microstructural characterization. The fractography and worn surface analysis were examined by using scanning electron microscopy. Energy dispersive X‐ray spectroscopy is used to show the presence of nanoparticles in casting. After three multi axial forging passes, the average grain size was reduced up to 4.2 μm as cast and 1.15 μm in nanocomposite. The wear resistance, microhardness and tensile strength of multi axial forging processed nanocomposite were significantly improved. All improved mechanical and wear properties cause the material one step towards sustainability.

Optimization of process variables and characterization of mechanically agitated ceramic‐microsphere reinforced aluminium composite

AbstractThis study aims to investigate the effect of stir‐casting process parameters, including stirring speed, stirring time, and weight % of the ceramic microsphere, on the fabrication of an aluminium 6061‐ceramic microsphere composite. Experiments are conducted using a full‐factorial design approach to determine the effect of variables on mechanical properties. A field effect scanning electron microscope is used to analyze the fracture surfaces of the test specimen. Further, the results are subjected to the Anderson‐darling normality test to validate the accuracy of the model, and finally, an analysis of variance is performed to identify the most significant parameters that affect the mechanical properties. The results confirm the validity of the designed experimental model for enhancing the mechanical properties of the aluminium 6061‐ceramic microsphere composite. The optimum mechanical properties are attained for a stirring speed of 600 min−1, stirring time of 15 min, and 5 weight % of reinforcement. Furthermore, the weight percentage of the ceramic microsphere increase, the ductility of the composite decreases while its strength and hardness increase. Finally, the analysis of variance shows that all parameters significantly impact the mechanical properties of the designed composite.

Effect of impingement angle and impact velocity on slurry erosive wear behaviour of particulate reinforced aluminium composites

Effect of impingement angle and impact velocity on slurry erosive wear behaviour of particulate reinforced aluminium composites

Mechanical Property Performance of Fe-SnS Hybrid Reinforced Aluminum Composites

Mechanical Property Performance of Fe-SnS Hybrid Reinforced Aluminum Composites

Data Evaluation of the Protection Performance of Maize Husk Particulate Reinforcements on 1170 Aluminium Alloy Corrosion in Dilute Electrolytes

Maize husk (MH) particulates at wt.% composition of 5% and 10%, and particle sizes of 150 and 300 um were added to the microstructure of 1170 aluminium alloy (Al) and analysed for their effect on the corrosion resistance of the maize husk reinforced aluminium composites Al/MH in 3.5% NaCl, 0.00625 M H2SO4 and 3.5% NaCl/0.00625 M H2SO4 solution by weight loss method. Protection performance results obtained at 264 h of exposure shows the MH particulates significantly enhanced the corrosion resistance of the Al/MH at 5 wt.% comp./150 um particle size (45%) and 5% wt./300 um particle size (30%) in 3.5% NaCl solution at 264 h. In 0.00625% H2SO4 solution, MH particulates significantly weakened the corrosion resistance of the Al/MH composites at all MH wt.% comp./particle sizes. Protection performance data at 264 h varied from-58.77% to 8.77 % which are significantly below the threshold 20% protection performance values. However, in 3.5% NaCl/0.00625% H2SO4, protection performance data above 20% threshold was obtained for Al/MH composites at 10% wt. comp./300 um particle size, 5% wt. comp./150 um particle size and 10% wt. comp./300 um particle sizes (22.58%, 38.71% and 29.03%). Results from ANOVA statistical method shows MH particulate wt.% comp./particle size is the important determinant factors influencing the protection performance results of Al/MH composites compared to exposure time with statistical relevance factor values of 36.53%, 77.98% and 18% from the electrolytes. The proportion of data above 20% protection performance for CB and CS particulates in 3.5% NaCl solution is 0% at margins of error of 0%. The corresponding values in 0.05 M H2SO4 solution are 15.18% and 15.32% at margins of error of 40% and 43% while the values from 3.5% NaCl/0.05 M H2SO4 solution are 14.78% and 15.5% at margins of error of 35% and 50%. The proportion of data above 20% protection performance for Al/MH composite in 3.5% NaCl solution is 30% at margins of error of 14.2%. The corresponding values in 0.00625 M H2SO4 solution are 15% at margins of error of 15.42% while the values from 3.5% NaCl/0.00625 M H2SO4 solution are 63% at margins of error of 15%.

Copper coated graphene reinforced aluminum composites with enhanced mechanical strength and conductivity

Traditional methods to enhancing mechanical strength of metallic materials would result in the inverse effect on the conductivity and how to prevent this inversed relationship between strength and conductivity has been a long-known problem, especially for electrically conductive materials. Here we report a strategy that utilize copper coated graphene as reinforcement, concurrently enhancing both the mechanical strength and electrical conductivity of aluminum matrix. Copper coated graphene reinforced composites were fabricated through a sequence of procedures involving chemical deposition, ball milling, and vacuum hot-pressing sintering processes. Copper coating on graphene not only avoids graphene from agglomeration but also prevents the development of degraded Al4C3 phase as well as increasing the interface bonding and the electrical contact between reinforcements and the matrix. The composite possesses an ultimate tensile strength of 242 MPa and a conductivity of 34.5 MS/m, respectively, with introducing 0.5 vol% graphene, which is around 102% and 8.15% higher than the corresponding values for pure aluminum manufactured under the same circumstances. Compared to other routine methods, this approach effectively tackles the enduring challenge of reconciling the trade-off between strength and electrical conductivity in metallic materials.

Effect of SiC nanoparticle on microstructure and mechanical properties of graphene nanosheet (GNS) reinforced aluminum composites

Homogeneous dispersion of high-content GNS is the challenge and key to achieve high mechanical properties of graphene reinforced aluminum matrix composites (GNS/Al). In traditional methods, the homogeneous dispersion of GNS is often achieved by prolonging the ball milling time or increasing the ball milling energy, which is often accompanied by severe damage to GNS structure. Here, a two-step ball milling process was employed to introduce SiC nanoparticles (SiCnp) in GNS/Al composites, which improves the GNS distribution while also playing an additional strengthening role. The Al flakes with a large lateral to thickness ratio were produced by a first-step ball milling of SiCnp and Al powders. The obtained Al flakes effectively improved the dispersion efficiency of GNS and reduced the GNS structural damage. As a consequence, GNS and SiCnp were well dispersed and combined with Al matrix after hot extrusion. The nanograins were also obtained in the extruded (GNS+SiCnp)/Al composites, which were conducive to the strengthening of composites. Benefiting from the homogeneous dispersion of GNS, SiCnp and the hybrid enhancement effect between them, the extruded (GNS+SiCnp)/Al composites showed significant improvement in Young’s modulus, tensile strength and, in particular, work hardening capacity compared to GNS/Al composites by approximately 278%, yielding good comprehensive mechanical properties.

Optimization of Sintering Process Parameters by Taguchi Method for Developing Al-CNT-Reinforced Powder Composites

In powder metallurgy, the sintering process is a high-power consuming and critical process for better mechanical properties of composites due to proper diffusion of atoms. In this context, different sintering processes were investigated along with their sintering condition. The present work focused on optimizing conventional sintering process parameters for carbon nanotubes (CNTs) reinforced aluminum composites using Taguchi optimization methods. The Taguchi L9 orthogonal array (OA) experiment was considered for the investigation. CNT’s wt.%, sintering temperature, and time were chosen as process parameters in the sintering process, while macro-hardness and relative density were evaluated as performance evaluation characteristics. The signal-to-noise ratio (S/N) and ANOVA statistical procedures were utilized to evaluate the effect of sintering parameters/levels on the micro-hardness and relative density of the Al/CNTs composite sintered. ANOVA statistical analyses revealed that the CNTs wt.% significantly influences relative density (83.58%), followed by temperature (14.58%), whereas CNTs wt.% significantly influenced micro-hardness (77.75%), followed by temperature (13.64%). The sintering of Al/CNTs composites using these optimum conditions is recommended to reduce power consumption and enhance the quality of the sintered composite.

Investigation on Mechanical and Machinability Properties of Aluminium Metal Matrix Composite Reinforced with Titanium Oxide (TiO2) and Graphite (Gr) Particles

This research paper deals with the preparation process and testing of metal matrix composites comprising Aluminium alloy (Al 6061) as the base metal and Titanium oxide (TiO2) and Graphite (Gr) as reinforcements. Due to their high specific strength, superior malleability, lightweight, stiffness and excellent resistance to corrosion, oxidation and wear, the aluminium metal matrix composites are preferred in the automobile and industrial sectors for component manufacturing. No work reported on machinability properties of Titanium oxide (TiO2) and Graphite (Gr) reinforced aluminium composites so far. This study prepared and studied samples composed of variable proportions of titanium oxide and graphite. The samples were prepared using the stir casting method. While stirring, the required additives were added to the molten aluminium mixture. To perform the tests, the samples were prepared according to standard dimensions after solidification. The mechanical properties of the prepared composite were examined using various test procedures, such as strength and hardness. Scanning electron microscopy was used to examine the microstructure of the test composite samples. The EDAX test confirmed the presence of graphite and Titanium oxide in the aluminium based composite specimens. Furthermore, machining was done to study the cutting forces on the tool. The test results showed a significant impact of the reinforced materials on the mechanical and machinability properties of aluminium metal matrix composites. Gr decreases hardness, while TiO2 increases it. TiO2 and Gr reinforcements increase the tensile strength of Al 6061 composites. The addition of TiO2 decreased the composite's elongation. The proof strength of 2 % Al6061 was high, however it decreased with 3 % Gr and increased with TiO2 reinforcement. Reinforcements increase cutting forces during machining; when comparing the machining of Al 6061 to that of 3 % Gr and 5 % TiO2, a 50 % increase in cutting forces is noticed. However, excessive reinforcements may reduce cutting forces due to poor matrix-reinforcement adhesion. HIGHLIGHTS The mechanical and machinability properties of aluminium metal metrics reinforced with Titanium oxide (TiO2) and graphite (Gr) have not been reported so far in the literature. In this study, aluminium based composites reinforced with variable proportions of titanium oxide and graphite were prepared and studied. The fabrication process was done by stir casting by adding the required additives into the molten mixture of aluminium, followed by continuous stirring. The solidified samples were cut according to the standard dimensions and various test procedures were conducted to examine the mechanical and machinability properties of the prepared composites. Gr reduces hardness, whereas TiO2 enhances it. TiO2 and Gr reinforcements boost Al 6061 composite tensile strength. TiO2 addition reduced elongation of the composite. 2 % proof strength of Al 6061 was strong, however it dropped with 3 % Gr and rose with TiO2 reinforcement. Reinforcements results higher cutting forces while machining, however excessive supplements lower cutting forces may be due to poor matrix-reinforcement bonding. GRAPHICAL ABSTRACT

Mechanical strengthening and micro-mechanical modelling of newly fabricated 7068-aluminium/lightweight-high-entropy-alloy as aero-material

On account of their lower densities and distinct properties, lightweight high entropy alloys (LHEA) are gaining prominence in the fabrication of particulate reinforced aluminum composites. In lieu of this, present report was conceived to achieve strength and ductility improvement in aluminum-7068 aerospace alloy by the inclusion of highly flexible Al30Li20Mg10Be20Ti10Cu10 LHEA (at 4, 10, and 16 wt%) as reinforcing phase. From the experimental outcome, the X-ray diffraction of the composites depicted BCC and FCC phases derived from LHEA addition. As the LHEA dosage increased, these phases became more prominent. Meanwhile, CuAl2, and MgBe13 intermetallic phases were equally identified in the composites. Based on the microstructure, the particles were sparsely dispersed at 4%, evenly dispersed at 10%, and exhibited both dispersed and clustered particles at 16%. The identified phases and the morphology played significant role in the mechanical characteristics of the fabricated composites ensuing strength improvement. Likewise, the plastic deformability of the composites was enhanced, resulting in a boost in strain hardening sensitivity and a decrease in necking susceptibility. The strengthening mechanism and the micro-models are herein discussed. According to the results, optimal efficacy was deduced at 10% LHEA.

An investigation on the effect of Al4C3 on microstructure and mechanical properties of carbon nanotube reinforced aluminum composite

In carbon nanotube (CNT) reinforced metal-matrix composites, a strong interface between CNTs and the matrix is essential for an effective load transfer. Otherwise, the excellent qualities of CNTs would virtually remain unexploited. The aim of this study is to investigate the effect of Al4C3 formation on the mechanical properties of CNT/Al composites. Composite powders were produced through a three-stage process; First, CNTs were sufficiently crushed via high-energy milling of 20 h. Then, the crushed CNTs were ultrasonically mixed with raw CNTs (in an ethanol medium) followed by a wet milling process. Finally, different amounts of the obtained reinforcing agent (0.5, 1, 1.5, 2, and 3 wt.%) were milled with aluminum powders. Composite powders were subsequently consolidated using spark plasma sintering (SPS) process at two different temperatures (500 and 550 °C) For each sample, the amount of carbide was calculated in a semi-quantitative manner using Raman spectroscopy. The results of phase analysis and mechanical-behavior evaluations showed that Al4C3 formation, due to the consumption of highly-activated crushed CNTs, could improve the interface bonding state while maintaining CNTs structural integrity. Moreover, mechanical and wear tests revealed that the optimum properties were obtained for the composite reinforced by 1wt.% processed carbon nanotubes (PCNTs) and SPSed at 550 °C for 10 min. These findings can open up a window toward the realm of design and processing of CNT/Al composites.

Investigations on the microstructure and properties of yttria and silicon carbide reinforced aluminium composites

Powder Metallurgy (PM) was used to synthesize SiC (0, 5, 10, 15 & 20 wt%) and 1 wt% Yttria (Y2O3) reinforced aluminium (Al) metal matrix composites. The Al–SiC–Y2O3 hybrid composites samples were prepared for density (ρ), hardness (VHN), mechanical, tribological, and microstructural studies in accordance with ASTM standards. SEM images revealed an even spreading of SiC particles throughout the Al matrix and composition was verified by the characterization techniques. The addition of SiC and Y2O3 to their respective composites improved the VHN and ‘ρ’. The compressive strength (CS) of Al–SiC–Y2O3 composites increased while increasing the SiC. The higher compression strength (405 MPa) was obtained for the Al − 1 wt% Y2O3-20 wt% SiC- hybrid composites. The thermal conductivity (K) of Al–SiC–Y2O3 samples diminishes, as the hard SiC particles are gradually added. Furthermore, it was observed that accumulative the wt% of SiC in the aluminium metal matrix (AMMC) results in a novel material with a decreased wear rate. The better properties was achieved for the samples contain 20 wt% of SiC content in Al − 1 wt% Y2O3 matrix.

Analysis of the effect of Zea Mays husk particulate reinforcement on 1170 Aluminium corrosion in a simulated industrial environment

The worldwide need for lightweight, high-quality, high-performance, and low-cost materials is prompting a change in emphasis from unreinforced materials to reinforced/composite materials. The mechanical properties of the MHP reinforced aluminum composite are compared to those of the unreinforced metal using the data on the corrosion performance of maize husk particulate reinforcement on high 1170 Aluminium alloy in 0.00625 M H2SO4, 3.5 wt.% NaCl and a mixture of both solutions was studied using weight loss technique to determine the corrosion rates of the specimens. Optical microscopic analysis was also carried out on the specimens to determine the effect of the reinforcement on the microstructural properties of the material before and after corrosion. The corrosion rates calculated from the weight loss study revealed differences in the corrosion characteristics of the specimens in the various solutions when compared to the control specimen. The presence of reinforcement in the matrix was discovered to positively impact the corrosion behavior of composite materials via the production of corrosion resistant oxides. The electrochemical properties of maize husk enhances the corrosion resistance of the composite due to its ability to form a protective oxide film and chemically resistant inclusions on the surface of the material.

Effect of impingement angle and impact velocity on slurry erosive wear behaviour of particulate reinforced aluminium composites

Effect of impingement angle and impact velocity on slurry erosive wear behaviour of particulate reinforced aluminium composites

Preparation and quasi-static compression properties of hybrid aluminum matrix syntactic foam reinforced with glass cenospheres and silicon carbide nanowires

Conventional hybrid aluminum matrix syntactic foam with various hollow fillers shows low density and high densification strain. However, its peak stress can hardly be increased, resulting in a limited improvement in the energy absorption capacity. Although composites can be reinforced by adding ceramic nanoparticles, it is difficult to achieve dispersion of both hollow and dense fillers in the metal matrix due to their distinct density difference. In this study, we use silicon carbide nanowires reinforced aluminum swarf as the source of ceramic fillers, and prepare hybrid aluminum syntactic foam reinforced by both glass cenospheres and silicon carbide nanowires. The resulting syntactic foam shows low density of 1.3 g cm −3 , high peak stress of 128.6 MPa, and high energy absorption capacity of 60.70 MJ m −3 . Moreover, we demonstrate a novel way to recycle silicon carbide reinforced aluminum composites for reprocessing. • HASF reinforced with a hollow and a dense nanowire filler. • Glass cenospheres and SiCnw forming high dispersion of microscale domains in HASF. • Reprocessing both metal matrix and SiCnw fillers at the same time. • HASF showing strength of 128.6 MPa and energy absorption capacity of 60.70 MJ m −3 .

Tensile behavior and failure mechanism of 3D woven fabric reinforced aluminum composites

This paper aims to study the mechanical behavior and the complicated failure mechanism of a novel Al matrix composites reinforced with 3D orthogonal woven carbon fiber. The quasi-static tensile behavior, local stress response and progressive failure process are investigated via numerical and experimental approach. According to the microstructure at fiber and yarn scale, microscopic and mesoscopic finite element models were established to carry out multiscale simulation. The calculated tensile stress-strain curve is basically in accordance with the experimental curves, where the elastic moduli, tensile strength, and elongation are 118.6 GPa, 777.3 MPa and 0.84%, respectively. Local stress distribution of the matrix pocket and yarns exhibits apparent periodicity and heterogeneity, which is related to the specific fabric architecture. Interface debonding induces the local damage of matrix alloy and transverse cracking of binder and weft yarns successively, resulting in nonlinear response of the tensile curves. The catastrophic rupture of the composites is caused by the axial fracture of warp yarns that resulted from the combination of matrix failure and transverse yarns cracking. The fracture morphology of binder and weft yarns is flat and that of warp yarns exhibits limited fiber pull-out, which can be interpreted by the predicted failure mode. Based on the validated model, the influence of fabric structure parameters on the macroscopic properties was further evaluated. The results indicate that the increase of warp or weft density could improve the tensile strength and elastic modulus, but the tensile elongation decreases with the increase of weft density.