Graphene Reinforced Aluminum Matrix Composites Research Articles

Effect of surface microporous copper coatings on corrosion properties of graphene-reinforced aluminium matrix composites

ABSTRACT It is difficult to assess the temperature and pressure resistance of the existing soluble bridge plug seal ring used in fracking for shale gas reservoirs, to go with its high plasticity and good solubility. To overcome this shortcoming, aluminium matrix composites with the addition of 0%, 0.5% and 1.0% of graphene were prepared by spark plasma sintering. Uniaxial static pressure test results show that the composite has the maximum compressive strength and compression ratio when the graphene content is 0.5%. Microporous copper coatings were prepared on graphene/1070 aluminium surface by electroless plating. The synergistic effect of the surface microporous copper coating and the internal graphene on the corrosion performance of 1070 aluminium alloy was analysed by the weight loss and electrochemical methods. The results showed that the surface microporous copper coatings could significantly improve the uniform corrosion rate and pitting depth of graphene/1070 aluminium.

Influence of interposed graphene sheets on mechanical and electronic properties of Al/graphene superlattice

Graphene-reinforced aluminum matrix composites have drawn remarkable attention in several fields of high-tech industries, but the understanding of their material properties remains unclear. This work reports a first-principles study of interface binding nature, mechanical strength, and electronic properties of aluminum/graphene (Al/G) composites using superlattice models as varying graphene content. Our calculations reveal the weak binding between Al and graphene layers with no new chemical bonding at the interface and the gradual decrease in binding strength as increasing graphene content. While demonstrating the enhancement of mechanical strength by interposing graphene layers, the critical value of graphene content for keeping ductility is determined to be 14.7%. Atom-projected band structures and local density of states are analyzed to get an insight into electronic conductance of superlattices.

Synthesis and characterization of CeO2 modified graphene oxide with improved wettability

In this paper, CeO2 nanoparticles coated graphene oxide (CeO2@GO) nanocomposites were synthesized by a modified hydrothermal method. The morphology and structure of CeO2@GO nanocomposites were characterized systematically. Moreover, the wettability behavior of GO before and after coating CeO2 nanoparticles was investigated. It was found that the CeO2 nanoparticles with an average diameter of ~10 nm were successfully loaded on the GO surface. TEM investigations showed that the CeO2 nanoparticles loaded on the GO surface were dominated by an octahedral shape, and the main exposed surfaces of CeO2 nanoparticles were {111} facets. This was because the closed-packed plane CeO2 {111} had the lowest surface energy. After loading CeO2 on the GO surface, the contact angle between Al drop and CeO2@GO substrate was reduced from 166° to 70° by calculation, attributing to that the CeO2 coating increased the surface free energy of GO. This work provides a feasible method to prepare the rare earth oxides coated GO nanocomposites and shows potential applications in the field of graphene reinforced aluminum matrix composites (AMCs).

Effects of the graphene content on mechanical properties and corrosion resistance of aluminum matrix composite

Graphene with excellent mechanical and physical properties has shown its great application potential in aluminum matrix composites. In this paper, graphene oxide nanosheets with negative charges were fabricated by the Hummers' method and they are absorbed on the treated aluminum powders with positive charges by electrostatic self-assembly. Then, graphene reinforced aluminum matrix composites (Gr/Al) were prepared by powder metallurgy. The effects of the Gr content on mechanical performance and corrosion resistance were investigated. The results show that Gr is distributed at the boundary and bonds well with aluminum in Gr/Al composite. Mechanical properties of the composite initially increase then decrease with the increase of Gr content. When the Gr content reaches 0.3 wt%, the ultimate tensile strength reaches 110 MPa and the wear coefficient is 0.39. However, the corrosion resistance decreases with increasing the Gr content and the corrosion mechanism is also investigated in details.

Explanatory Machine Learning Accelerates the Design of Graphene-Reinforced Aluminium Matrix Composites with Superior Performance

Addressing the exceptional properties of aluminium alloy composites reinforced with graphene, this study presents an interpretable machine learning approach to aid in the rapid and efficient design of such materials. Initially, data on these composites were gathered and optimised in order to create a dataset of composition/process-property. Several machine learning algorithms were used to train various models. The SHAP method was used to interpret and select the best performing model, which happened to be the CatBoost model. The model achieved accurate predictions of hardness and tensile strength, with coefficients of determination of 0.9597 and 0.9882, respectively, and average relative errors of 6.02% and 5.01%, respectively. The results obtained from the SHAP method unveiled the correlation between the composition, process and properties of aluminium alloy composites reinforced with graphene. By comparing the predicted and experimental data in this study, all machine learning models exhibited prediction errors within 10%, confirming their ability to generalise. This study offers valuable insights and support for designing high-performance aluminium matrix composites reinforced with graphene and showcases the implementation of machine learning in materials science.

Large scale production of graphene aluminum composites by stir casting: Process, microstructure and properties

Graphene has recently garnered significant attention as an exceptional nanofiller for aluminum (Al) matrix composites due to its remarkable mechanical strength, elevated thermal and electrical conductivities. For practical industrial applications, it is necessary to develop large-scale production technology. To this end, we have utilized a scalable stir-casting process to fabricate graphene-reinforced aluminum matrix composites. The microstructure, mechanical properties, electrical and thermal conductivities of the composites with varying graphene contents were characterized. Through testing, it was confirmed that graphene remained intact within the aluminum matrix during the stir-casting process, and the damage to the graphene sheet during the fabrication of composites was slight. High-resolution microscopic observation shows that aluminum, graphene and aluminum carbide co-exist within the composites. Compared to its pure aluminum counterpart, the Vickers hardness of the optimal composite sample (with a graphene content of 0.2 wt.%) exhibits a significant increase of 42%. Also, this superior composite sample exhibits a remarkable increase of 5% and 38% in its electrical and thermal conductivities respectively. The performance evolution and improvement mechanisms have been thoroughly investigated and revealed. The test results suggest that preformed blocks and stir casting are promising technologies for the large-scale production of graphene-aluminum composites.

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.

Wear properties of graphene-reinforced aluminium metal matrix composite: A review

Abstract The recent advancement in graphene-reinforced aluminium matrix composites improves wear behaviour in the production of lightweight and high-performance nanocomposites. Considerable works have been devoted to using graphene nanoparticles as solid self-lubricants to increase wear resistance, minimise friction coefficients, improve service efficiency, and extend the lifespan of related sliding components. In general, wear behaviour often depends on the homogeneous distribution of graphene in the aluminium matrix. The non-uniform distribution of reinforcement due to the tendency of graphene to agglomerate in aluminium matrix and its poor wettability becomes a challenge in developing optimum functional of composites. The wettability of graphene can be enhanced by proper processing methods and sufficient addition of magnesium that can improve the wear and frictional properties of the produced composites. Hence, this review article provides recent findings and the influence of graphene as reinforcement materials in composites, including the effects on wear behaviour and friction properties. This article also discusses new advancements in the effect of graphene in self-lubricating aluminium matrix composites and the impact of reinforcement on the wear mechanisms of the composites. The future direction of the wear properties of MMCs is also covered at the end of the review.

Mechanical Property and Corrosion Behavior of Powder-Metallurgy-Processed 3D Graphene-Networks-Reinforced Al Matrix Composites

Three-dimensional graphene networks (3DGN) have the potential to be used as a reinforcement for aluminum matrix composites due to their unique wrinkled structure and cost-effectiveness. In this work, the mechanical properties and corrosion resistance of 3DGN in Al matrix were systematically investigated. 3DGN/Al composites with weight ratios of 0, 0.075, 0.150, 0.225, and 0.300 3DGN were prepared by powder metallurgy following by ball mill and spark plasma sintering. Results revealed that the densification of 3DGN/Al composites slightly decreases with the increase of 3DGN content. Increased hardness without loss of ductility was recorded compared to the pure aluminum sample prepared under the same experimental conditions. 3DGN/Al composites exhibit higher corrosion currents density than that of pure aluminum, which shows that the addition of 3DGN reinforcement aggravates the corrosion of aluminum. This study can be used as a reference for future research on the effect of graphene on the various properties of graphene-reinforced aluminum matrix composites.

Numerical Simulation of Thermal Conductivity of Graphene Reinforced Aluminum Matrix Composites

In order to develop materials with high thermal conductivity, aluminum matrix composites are attracting much attention. The heat transfer ability of graphene-reinforced aluminum matrix composites was numerically simulated with the finite element method. A composite model of 3D many-particle stochastic distributions is developed. The effect of temperature, volume fraction of graphene, graphene shapes and graphene orientation heat transfer capacity of composite materials was researched. Studies have shown that that the graphene volume fraction, graphene shapes and graphene orientation were significant factors for the heat transfer of the composites. As the graphene content increases, the temperature transfer capacity of the composite increases. The disc-shaped graphene with an orientation angle of 45° in composites can obtain an enhancement in the heat transfer ability of the composites.

Finite element modeling on micro-machining of graphene-reinforced aluminum matrix composites

Finite element modeling on micro-machining of graphene-reinforced aluminum matrix composites

Nickel-encapsulated graphene reinforced aluminum matrix composites with increased mechanical strength and electrical conductivity

Nickel-encapsulated graphene reinforced aluminum matrix composites with increased mechanical strength and electrical conductivity

A systematic study of interface properties and fracture behavior of graphene/aluminum: Insights from a first-principles study

In-depth study of graphene/aluminum interface properties with different structures is of great significance for improving the toughness and strength of next-generation aluminum alloys. In this paper, different structural models of Al matrix and graphene/Al composites were studied by first-principles calculations, revealing the interface strength and fracture behavior mechanism. The stability, fracture energy and tensile strength of different surfaces of Al(1 0 0), Al(1 1 0), and Al(1 1 1) were investigated by first-principles calculations, and the interfacial strength and fracture behavior of three common surfaces were revealed. The Al(1 1 1) surface has the lowest surface energy, lowest fracture energy and lowest tensile stress intensity. On this basis, we considered coating graphene on Al(1 1 1) surface, and then investigated the effects of C vacancies and Si doping on the fracture energy and tensile strength of the composites. The results show that with the increase of C vacancies and the increase of Si introduction concentration, the fracture energy and tensile stress strength of the system tend to increase. The density of states calculations show that there is a certain hybridization effect between Al-3s, Al-3p and C-2p, Si-3p orbitals, forming s-p hybrid orbitals. The most stable interfaces contain low-energy state electrons with the most uniform electron distribution, which is a key factor for interface stabilization and strengthening. Our theoretical research results have certain guiding significance for the experimental synthesis of graphene-reinforced aluminum matrix composites and the improvement of the strength of aluminum and aluminum alloys.

Heteroatom Modification Enhances Corrosion Durability in High-Mechanical-Performance Graphene-Reinforced Aluminum Matrix Composites.

The antagonism between strength and corrosion resistance in graphene‐reinforced aluminum matrix composites is an inherent challenge to designing reliable structural components. Heteroatom microstructural modification is highly appreciated to conquer the obstacle. Here, a bottom‐up strategy to exploit the heterogeneous phase interface to enable high corrosion durability is proposed. Deformation‐driven metallurgy derived from severe plastic deformation is developed to produce Mg‐alloyed fluorinated graphene structures with homogeneous dispersion. These structures allow for absorbing corrosion products, forming a dense protective layer against corrosion, and local micro‐tuning of the suppression of charge transfer. This results in superior corrosion resistance with an outstanding strength‐ductility balance of the composites via ultrafine‐grained and precipitation strengthening. The anti‐corrosion polarization resistance remains 89% of the initial state after 2‐month immersion in chloride‐containing environment, while the ultra‐tensile strength and elongation of 532 ± 39 MPa and 17.3 ± 1.2% are obtained. The economical strategy of heteroatom modification broadens the horizon for anti‐corrosion engineering in aluminum matrix composites, which is critical for the design of carbonaceous nanomaterial‐reinforced composites to realize desired performances for practical applications.

Microstructure analysis, tribological correlation properties and strengthening mechanism of graphene reinforced aluminum matrix composites

In this paper, graphene reinforced aluminum matrix composites are successfully prepared by high-energy ball milling. The results show that no graphene agglomeration is found in the mixed powder. The complex composites prepared by high energy ball milling and powder metallurgy have approximately 4–5 layers of graphene and the thickness of single-layer graphene is approximately 0.334 nm. The final experimental results confirm the formation of compound AlC3 in the microstructure, and its diffraction spot index is (overline{2 }00), (overline{1 }1overline{1 }) and (11overline{1 }). The maximum friction coefficient is 0.126, and the average friction coefficient is 0.027, suggesting good wear resistance and corrosion resistance. Additionally, the friction corrosion mechanism of the material is deeply analyzed. The results of strengthening mechanism analysis show that the main strengthening mechanism of the materials designed in this experiment is thermal mismatch strengthening. It can be concluded that the yield strength of the material calculated by the modified model is 227.75 MPa. This value is slightly lower than the calculated value of the general shear lag model (237.68 MPa). However, it is closer to the yield strength value of the actual material (211 MPa).

Effect of Content and Size of Reinforcements on the Grain Evolution of Graphene-Reinforced Aluminum Matrix Composites.

Graphene-reinforced aluminum matrix composites (GRAMCs) attract great interest in industries due to their high performance potential. High-temperature processes such as sintering and aging are usually applied during the preparation of GRAMCs, leading to grain coarsening that significantly influences its properties. In this work, a modified 3D Monte Carlo Potts model was proposed to investigate the effect of content and size of graphene on the grain evolution during the heat treatment of GRAMCs. Grain growth with graphene contents from 0.5 wt.% to 4.5 wt.% and sizes from 5 μm to 15 μm were simulated. The grain growth process, final grain size and morphology of the microstructure were predicted. The results indicated that both the content and size of the reinforcements had an impact on the grain evolution. The pinning effect of grain size can be enhanced by increasing the content and decreasing the size of graphene. Agglomeration and self-contacting phenomena of the graphene arose obviously when the contents and sizes were relatively high. The average grain size decreased by 48.77% when the content increased from 0.5 wt.% to 4.5 wt.%. The proposed method and predicted regulations can provide a reference for the design and fabrication of GRAMCs.

A review on microstructures and properties of graphene-reinforced aluminum matrix composites fabricated by friction stir processing

Adding reinforcement is an effective way to improve the properties of aluminum alloy. Graphene is an ideal reinforcement for the fabrication of aluminum matrix composites (AMCs) due to its excellent comprehensive performances. Friction stir processing (FSP), as a novel processing technology, is an ideal candidate for fabricating graphene-reinforced AMCs with high performances under appropriate conditions. The present paper firstly summarizes the structure-property characteristics of graphene-reinforced AMCs fabricated by FSP. Then the influences of process conditions on the structure-property evolutions of the composites are discussed. It is found that the addition of graphene leads to grain refinement and texture variation of the stir zone during FSP. Besides, mechanical properties, electrical conductivity, thermal conductivity, tribological property and corrosion resistance of the AMCs are considerably affected by the content of graphene and various microstructure evolutions induced by the added graphene. Composite of reinforcement, adding method of graphene, FSP parameters, FSP pass number and FSP path pattern are critical process conditions that determine the microstructures and properties of the AMCs. The present paper not only concludes major findings of the previous researches but also suggests future recommendations for fabrication of graphene-reinforced AMCs through FSP.

Preparation and Properties of Modified Graphene Reinforced Aluminum Matrix Composites

In order to solve the problem of agglomeration of graphene in preparation of composites, GN-CeO2 powders with even dispersion were obtained by a hydrothermal reduction method, which involved modifying the surface of acidified graphene by cerium nitrate. Then, Al/GN-CeO2 composite powders and materials were prepared by high-energy ball milling and vacuum hot pressing, respectively. The details were investigated, including the effect of modification process on the surface morphology and functional groups of graphene and modification time on the properties of Al/GN-CeO2 composites. The result shows that the functional groups and defects of graphene were added by the treatment of acidification process, which is beneficial to the composite of graphene and CeO2 particles. The quantity of CeO2 deposition on graphene surface increased with the duration of hydrothermal reduction time. After 6 h modification, the properties of the composites performed best. Compared with Al/GN composites, the tensile strength of the modified composites was increased from 284 MPa to 321 MPa; and the tensile strain rate of the modified composites was increased to 12.3%；the hardness of the modified composites was increased from 97.1 Hv to 99.5 Hv；the conductivity of the modified composites was increased from 29.84%IACS to 33.21%IACS.

Simultaneously enhanced strength and ductility of Al matrix composites through the introduction of intragranular nano-sized graphene nanoplates

Simultaneously achieving high strength and ductility is a critical issue for graphene reinforced aluminum matrix composites, which couldn't be resolved by the conventional mechanical milling-powder metallurgy technology due to the following reasons. On one hand, the low addition of graphene in the matrix traceable to its poor dispersibility limits the further strength improvement. On the other hand, the introduced graphene tends to distribute into grain boundaries rather than inside grains, which would result in stress concentrations at grain boundaries and localized strains, leading to the poor ductility of graphene/Al composites. In this work, intragranular nano-sized graphene nanoplates with high-content were dispersed in the matrix uniformly by a modified ball milling strategy, which induces that the strength and uniform elongation of the composites were simultaneously enhanced due to the improved work hardenability. Furthermore, the strengthening and toughening mechanisms were also discussed. This work offers a new insight into the fabrication and design of graphene/Al composites with both high strength and ductility.

Recent progress in graphene-reinforced aluminum matrix composites

Recent years witnessed a growing research interest in graphene-reinforced aluminum matrix composites (GRAMCs). Compared with conventional reinforcements of aluminum matrix composites (AMCs), graphene possesses many attractive characteristics such as extremely high strength and modulus, unique self-lubricating property, high thermal conductivity (TC) and electrical conductivity (EC), and low coefficient of thermal expansion (CTE). A lot of studies have demonstrated that the incorporation of graphene into Al or Al alloy can effectively enhance mechanical and physical properties of the Al matrix. The purpose of this work is aimed to trace recent development of GRAMCs. Initially, this paper covers a brief overview of fabrication methods of GRAMCs. Then, mechanical, tribological, thermal and electrical properties of recently developed GRAMCs are presented and discussed. Finally, challenges and corresponding solutions related to GRAMCs are reviewed.