Graphene-reinforced Metal Matrix Composites Research Articles

Graphene-reinforced metal matrix composites produced by high-pressure torsion: a review

Graphene-reinforced metal matrix composites produced by high-pressure torsion: a review

Progress of highly conductive Graphene-reinforced Copper matrix composites: A review

Enhancing the electrical conductivity of metals remains a critical challenge, as it directly determines the transmission efficiency of power electronic systems. Graphene-reinforced metal matrix composites have garnered widespread attention due to their exceptional electrical conductivity and low-temperature coefficient of resistance. This review thoroughly examines the intrinsic physical properties of Graphene and Cu, identifying specific obstacles in developing highly conductive composite materials. Despite the weak van der waals interactions between Graphene and Cu, the work principle and interaction mechanism between Cu and Graphene are elucidated. The primary focus of this review is to explore methods for enhancing the electrical conductivity of Cu/Graphene composites through different design strategies and processing techniques. The more complex and critical factors encompass the quality of raw materials, processing techniques, dimensional precision, crystallographic orientation, and the interfacial properties between Graphene and Cu. The perspectives on the research gap and further development trends of Cu/Gr composites are also discussed.

Interatomic potentials for graphene reinforced metal composites: Optimal choice

Graphene reinforced metal matrix composites represent a promising class of materials for high-strength surface coatings because of their high strength and ductility. This study reports the application of different interatomic potentials to correctly describe the interaction between graphene and metals (Al, Cu, Ni, and Ti) by molecular dynamics. Both simple pair potentials, such as Lennard-Jones and Morse, and many-body potentials, such as bond order potential are applied for the simulation of a graphene/metal system at room temperature. Three different structures are considered: (i) graphene interacting with one metal atom; (ii) graphene interacting with a metal nanoparticle, and (iii) three-dimensional graphene network filled with metal nanoparticles. We first determine the potential energy that any graphene/metal system can reach during exposure at 300 K; then, we analyze the interaction dynamics for all considered systems and all potentials. A considerable difference in the interaction between metal nanoparticles with planar and folded graphene was found. For graphene/Ni, graphene/Cu, and graphene/Ti, the Lennard-Jones and Morse potentials provide accurate energetic and structural properties of the studied structures; they also describe interaction in the graphene/metal system in a similar way, at variance with bond-order potential. For graphene/Al, the Tersoff and Morse potentials describe the interaction better than Lennard-Jones. For the simulation of graphene/Me system, the optimal choice of the potential for different structures is of crucial importance. The presented analysis of the interatomic potentials appears to be promising for realistic and accurate simulations of graphene reinforced metal composites.

Mechanical and conductivity properties of 6061Al matrix composites reinforced with different pH Cu-coated graphene

ABSTRACT The lightweight designs of automobiles and space shuttles have raised the bar for aluminum (Al) and its alloys. Graphene (GP) has found widespread application in aluminum matrix composites due to its exceptional mechanical, electrical, and thermal properties. In this study, a successful preparation of 6061Al reinforced with GP was achieved through a powder metallurgy method. This involved mixing GP with 6061Al alloy powders via ball milling, followed by hot-pressing sintering to produce the final GP-reinforced Al alloy nanocomposite. The effect of the pH value of the plating solution on the electroless plating of GP has been studied for the first time. The results show that the strength of the aluminum-matrix composites with copper plating has been significantly improved compared with that of the composites without copper plating. When the pH value of the plating solution is 12, the tensile strength of the composites obtained has been increased by 60.41%. Compared with the matrix material, the conductivity of the composite material has also increased. This work shows that the mechanical behavior of graphene-reinforced metal matrix composites (MMCs) can be improved by adjusting the distribution of graphene coatings, which is of great benefit for the preparation of high strength and lightweight composites with good electrical conductivity.

Crystal plasticity finite element modelling and mechanical deformation mechanism of nanolaminated graphene reinforced metal matrix composites

Metal matrix composites with certain hierarchical structures are potential to break out the conflicts between strength and toughness. Nano-carbon like graphene (Gn) reinforced metal matrix composites with nanolaminated structures have been largely developed to overcome this issue. However, the plastic deformation mechanism hiding behind the nanolaminated structures is still lacking. In this study, crystal plasticity finite element simulations and composite structure modeling are combined in order to uncover the mechanical deformation behavior of nanolaminated Gn/Al composites. Different lateral Gn sizes of 180, 360 and 720 nm are considered, while the hybrid lateral Gn sizes of 180 and 720 nm are applied as well. Good consistency between experimental and numerical results indicates the reliability of performed simulations. It is found that the strengthening and hardening behaviors of Gn/Al composites are dominated by Gn rather than Al matrix. The edges of Gn serving as a major dislocation nucleation source produce localization of plastic deformation, while the interiors of Gn activate more slip systems but reduce total shear strains. The edges and interiors of Gn determine the stability of plastic deformation of Gn/Al composites; large edge vs. interior area of Gn will lead to early necking. The rule of mixture fails in predicting the peak tensile strength and tensile strain of Gn/Al composites with hybrid lateral Gn sizes, because the microscopic plastic deformation can largely localize around 180 nm Gn in these hybrid Gn/Al composites. This work is enlightening to design and develop novel smart metal matrix composites.

Spall characteristics of three-dimensional graphene networks with embedded copper: A molecular dynamics study

The phenomenon of shock-induced spallation has garnered significant interest in both scientific and industrial circles. Laminated graphene embedded in graphene-reinforced metal-matrix composites have been shown to improve mechanical properties. This study systematically investigates the dynamic response and spall failure of a three-dimensional graphene network (3DGN) with embedded copper composites (3DGCu) and its dependence on the grain sizes (D). Firstly, increasing the wt% of graphene results in significant increase of shock wave speed due to the intrinsic high modulus of graphene, whilst leading to a reduction in shock pressure. Spallation of 3DGCu at low shock velocity is observed, which is dominated by the bonded interaction at the graphene-metal interface. However, the 3DGCu with higher graphene content (smaller D) exhibits both low density and superior spall resistance. In particular, in the sample with 60 wt% graphene, the complete spallation has never occurred and still maintains a relatively high spall strength within the impact velocity of 3.0 km/s. This is due to the remarkable capacity for 3DGN to absorb the kinetic energy during tension. In addition, during shock loading, the graphene component is responsible to the tension loading, whereas the copper metal matrix undergoes compression, leading to a stable post-shock length. These findings offer a novel approach for tailoring the dynamic properties of advanced graphene-based nano-composites with potential applications in extreme environments.

Recent progress on corrosion mechanisms of graphene-reinforced metal matrix composites

Abstract For components serving in high temperature, humidity, and salinity marine corrosive environment, it is vital to analyze the causes of corrosion behavior and corrosion mechanisms. Metal matrix composites (MMCs) are commonly used materials for offshore equipment. In this work, the corrosion factors of MMCs in marine environments are analyzed from the characteristics of high temperature, humidity, and salinity service environment, and the corrosion mechanisms are summarized. Graphene (Gr) has excellent comprehensive properties and great potential for applications in metal protection materials. In recent years, research into Gr anti-corrosive applications encompasses two aspects: pure Gr coatings and Gr composite coatings. Gr applied in MMCs is yet to be extensively studied. Therefore, this study analyzes the corrosion resistance of Gr–metal composites and discusses the corrosion resistance mechanisms of Gr-reinforced MMCs, which provides a reference for the design of Gr-reinforced metal composites and the optimization of corrosion resistance performance. Finally, future development directions for Gr–metal composites are proposed, and the critical factors such as defects, dispersion, content, size, arrangement, interface, and conductivity of Gr in the composites affecting their anti-corrosion properties are discussed.

Accelerating Density Functional Calculation of Adatom Adsorption on Graphene via Machine Learning

Graphene has attracted significant interest due to its unique properties. Herein, we built an adsorption structure selection workflow based on a density functional theory (DFT) calculation and machine learning to provide a guide for the interfacial properties of graphene. There are two main parts in our workflow. One main part is a DFT calculation routine to generate a dataset automatically. This part includes adatom random selection, modeling adsorption structures automatically, and a calculation of adsorption properties. It provides the dataset for the second main part in our workflow, which is a machine learning model. The inputs are atomic characteristics selected by feature engineering, and the network features are optimized by a genetic algorithm. The mean percentage error of our model was below 35%. Our routine is a general DFT calculation accelerating routine, which could be applied to many other problems. An attempt on graphene/magnesium composites design was carried out. Our predicting results match well with the interfacial properties calculated by DFT. This indicated that our routine presents an option for quick-design graphene-reinforced metal matrix composites.

Graphene-reinforced metal matrix composites: fabrication, properties, and challenges

Graphene-reinforced metal matrix composites: fabrication, properties, and challenges

Enhanced strength and toughness of Ni/graphene composite via three-dimensional graphene-like nanosheets network

This paper reports a novel strategy for fabricating the three-dimensional graphene-like nanosheets network (3D-GLNN) in a nickel (Ni) matrix composite through spark plasma sintering induced welding between graphene-like nanosheets grown on the surface of Ni foams. The in-situ constructed 3D interconnected GLNN architecture can significantly improve the load transfer capacity, thereby increasing the yield strength of the bulk composite. The crack bridging in the fracture process induced by the 3D-GLNN blocks the crack propagation during tensile deformation and results in significant strengthening and toughening. This study provides an innovative design idea (using the 3D-connected Ni foam as a template) to synergistically enhance the strength and strain-hardening capacity, thereby breaking the strength-ductility trade-off of graphene-reinforced metal matrix composites.

Effect of Processing Techniques on Interface Bonding of Graphene Reinforced Metal Matrix Composites: A Review

Effect of Processing Techniques on Interface Bonding of Graphene Reinforced Metal Matrix Composites: A Review

Quasi-continuous GNS network induced local dynamic recrystallization along interfaces in titanium MMCs under high strain rate loading

Despite extensive research on graphene reinforced metal matrix composites (MMCs) over the past decade, the microstructure evolution of the composites still remains inexplicable, especially for dynamic loading conditions. The present work adopted a Ti–6Al–4V composite reinforced with quasi-continuous graphene nanosheets (GNSs) networks to investigate the role of reinforcement and its architecture on the mechanical response, microstructure evolution, and failure mechanism at different loading rates via Hopkinson bar system, Raman and X-ray diffraction examination, transmission electron microscope, and electron backscatter diffraction system. The results reveal that GNSs provide a significant strength improvement, owing to the formation of a quasi-continuous network comprising of GNSs and in-situ produced TiC particles. It is also found with microstructural examination that the local deformation is primarily mediated by the matrix, for which abundant local dynamic recrystallization was detected along the network-matrix interface. This may account for the reduced strain rate sensitivity and a propensity for adiabatic shear band (ASB) under impact loading for the composites. The mechanism of action of the quasi-continuous GNS network architecture is discussed in terms of the strengthening, strain rate sensitivity and ASB propensity of the composites with a quantative assessment.

Influence of the residual oxygen amount in reduced graphene nanoplatelets on microstructure and mechanical properties of ZK60 matrix composites

Graphene nanoplatelets (GNPs) are commonly regarded as an ideal reinforcement for metal matrix composites because of their excellent mechanical properties. However, these excellent properties cannot be fully exploited due to GNPs aggregation and poor bonding interface. In the present investigation, GNPs with different residual oxygen amount were prepared by adjusting the amount of KMnO4 oxidant using the modified Hummers method as well as thermal reduction. The GNPs-reinforced ZK60 matrix composites (GNPs/ZK60) were prepared through stir casting. Structure characterization indicates there are C–O, C–O–C and C–CO oxygen-containing functional groups on the synthesized GNPs, among which all C–CO and parts of C–O groups are broken and react with Mg to form MgO particles. The formed interfaces in terms of MgO in the GNPs/ZK60 composites are MgO/Mg, having a semi-coherent interface structure, and MgO/GNPs, having an incoherent interface structure. The sandwich interface structure of Mg/MgO/GNPs improves the interface bonding, in which the ultimate tensile strength and elongation of the 0.05 wt.%GNPs-4/ZK60 composite reached 261 MPa and 12.1%, increasing 37.4% and 128.3%, respectively, compared with those of the monolithic matrix. It is suggested the present work might offer a design guideline for graphene reinforced metal matrix composites.

Construction of graphene network in Ni matrix composites: A molecular dynamics study of densification process

Graphene network (GN) reinforced metal matrix composites have been proved to possess a combination of high strength and good ductility, but the formation mechanism of GN, which serves as the source of excellent mechanical properties, is rarely revealed. In this study, the construction of network architecture in graphene network reinforced Ni matrix composites (GN/Ni) is investigated by molecular dynamics (MD). Results show that discrete graphene sheets covered on Ni particles are assembled into an intact and continuous graphene network through interlayer and lateral connections. The curvature of GN walls caused by defects, together with the corners of GN near the intersections of multi Ni particles, realizes the 3D network architecture composed of nondevelopable surfaces. The GN intertwines intimately with the Ni matrix to construct an interlocking structure, where a robust interface is induced by the strong Ni–C interactions and the redistribution of internal stress. Besides, owing to the restricted atomic motion of Ni matrix by GN during densification, dislocation accumulation near the GN is actualized in GN/Ni, as well as the grain refinement. This work can benefit the optimization of graphene reinforced metal matrix composites for fulfilling the strengthening and toughening potentials of GN.

Wrinkles-assisted nanocrystalline formation and mechanical properties of wrinkled graphene/aluminum matrix composites

The graphene-reinforced metal matrix composites (Gr/MMCs), prepared by additive manufacturing technology, render a wide range of promising applications. The graphene sheets in Gr/MMCs may get wrinkled during preparation, which renders a significant influence on crystalline texture and deformation behavior. Herein, molecular dynamics models of wrinkled graphene/aluminum (W-Gr/Al) composites are established to study the effect of graphene wrinkle angle on crystal texture of the metallic matrix during the sintering process and mechanical properties of the resulting composites. The results indicate that the sintering temperature significantly affects the molding quality of W-Gr/Al composites, promoting the transformation of sintering mechanism. Furthermore, new wrinkles appear on initially-wrinkled graphene surfaces during the sintering process, resulting in grain boundaries and twin boundaries (TBs), which facilitate the refinement of Al grains. Moreover, uniaxial compression tests reveal that the W-Gr/Al composites sintered at 900 K exhibit the highest Young’s modulus and yield strength. It has been demonstrated that the enhancement effect of composite originates from the skeleton network, consisting of wrinkled graphene and TBs. These results provide significant guidance for the design and development of Gr/MMCs.

Strong strain hardening in graphene/nanotwinned metal composites revealed by molecular dynamics simulations

In the present work, four types of graphene/nanotwinned (nt) metal composites are constructed by incorporation of graphene into nt-Au, nt-Ag, nt-Al and nt-Ni matrices, respectively. Their mechanical properties and deformation behaviors are investigated by using molecular dynamics (MD) simulations. Strong strain hardening is found in both Gr/nt-Au and Gr/nt-Ag due to fast structural transition. The transition begins with the propagation of partial dislocations, followed by lattice rotation with the formation of stacking faults, finally resulting in the formation of ultrahigh-density twins with high similarity to the experimental findings. The strain-hardening behavior can only be obtained under uniaxial compression along [1 -1 -2] direction, showing a high orientation dependence. Graphene wrinkles and symmetrical lattice structure in nt-metal matrices are two key factors for a smooth structural transition with strong strain-hardening in Gr/nt-Au and Gr/nt-Ag. However, there is no strain hardening in Gr/nt-Al and Gr/nt-Ni, as the wrinkling of graphene cannot induce the nucleation of dislocations in nt-Al and nt-Ni matrices. This work provides a valuable guideline for the design and application of graphene-reinforced metal matrix composites.

Ultrahigh-strength multi-layer graphene-coated Ni film with interface-induced hardening

Graphene-reinforced metal matrix composites exhibit excellent mechanical properties owing to dislocation impedance at the metal-graphene interface. Graphene coated on metal with composites fabricated using powder sintering can be applied as high-strength thin films across various fields (e.g., microelectromechanical systems, flexible electronics). In this study, a bilayer composite of multilayer graphene (MLG)-coated Ni is synthesized using the chemical vapor deposition (CVD) and transfer methods; mechanical properties are investigated using nanoindentation methods. MLG-coated Ni synthesized by CVD exhibits 195% and 470% increases in hardness and Young’s modulus, respectively, compared with single-layer Ni. In contrast, the Young modulus and hardness of MLG-coated Ni synthesized via the transfer method can be estimated using the rule of mixture for composite materials. Transmission electron microscopy (TEM) shows that in MLG-coated Ni synthesized by CVD, dislocations are dense and evenly distributed compared with that synthesized by the transfer method, leading to its high mechanical strength. Molecular dynamics (MD) simulations demonstrate that interface-induced hardening is effective in graphene-coated Ni(111) with a strongly coupled interface. Therefore, ultrahigh-strength MLG-coated metal films can be obtained by manipulating the interface property between the MLG and metal, offering the potential for use as a thin film resistor against external force.

In-Situ Synthesis of Graphene-Like Carbon Encapsulated Copper Particles for Reinforcing Copper Matrix Composites

Owing to the unfavorable wetting and density difference between graphene and copper, it remains challenging to achieve homogeneous dispersion of graphene for utilizing the unique nature of graphene in copper matrix composites. Here, we design an in-situ process to fabricate graphene-like carbon (GLC) reinforcing copper matrix composites: GLC can be directly fabricated on commercial copper particles using modified PECVD method followed by vacuum hot pressing, which is high-efficiency and can be massively produced for graphene reinforced metal matrix composites in industrial level. After hot pressing, the GLC with ultra low content (170 to 350 ppm) can be uniformly dispersed and tightly embedded within the copper matrix. A remarkable thermal conductivity enhancement efficiency of 85% and enhanced thermal conductivity (439 W m-1 K-1), accompanied by the higher wear resistance, can be obtained in our GLC reinforced copper matrix composites. In actual arc ablation performance measurement, the breakdown strength and relative arc ablation resistance of GLC/Cu composites can be significantly improved by 106.5% and 33.3% than pure copper, respectively, demonstrating GLC/Cu composites a promising candidate for application as high voltage electrical contacts.

Interfacial Strengthening of Graphene/Aluminum Composites through Point Defects: A First-Principles Study.

The relationship between point defects and mechanical properties has not been fully understood yet from a theoretical perspective. This study systematically investigated how the Stone–Wales (SW) defect, the single vacancy (SV), and the double vacancy (DV) affect the mechanical properties of graphene/aluminum composites. The interfacial bonding energies containing the SW and DV defects were about twice that of the pristine graphene. Surprisingly, the interfacial bonding energy of the composites with single vacancy was almost four times that of without defect in graphene. These results indicate that point defects enhance the interfacial bonding strength significantly and thus improve the mechanical properties of graphene/aluminum composites, especially the SV defect. The differential charge density elucidates that the formation of strong Al–C covalent bonds at the defects is the most fundamental reason for improving the mechanical properties of graphene/aluminum composites. The theoretical research results show the defective graphene as the reinforcing phase is more promising to be used in the metal matrix composites, which will provide a novel design guideline for graphene reinforced metal matrix composites. Furthermore, the sp3-hybridized C dangling bonds increase the chemical activity of the SV graphene, making it possible for the SV graphene/aluminum composites to be used in the catalysis field.

A review of graphene reinforced Cu matrix composites for thermal management of smart electronics

Heat dissipation remains a key challenge to be addressed, determining the performance and durability of smart electronic devices. Graphene reinforced metal matrix composites have been extensively studied as a thermal management material due to their high thermal conductivity and low coefficient of thermal expansion. The emphasis of this review is pivoted on the thermal conductivity enhancement of graphene reinforced Cu matrix composites developed in the recent literature. An overview of factors affecting thermal conductivity of composite namely defect processing route, density, graphene derivative, lateral size, concentration, alignment, graphene/matrix interfacial bonding and graphene modification are discussed. An extensive weightage is given to the processing route as it is the most influential factor in determining the enhancement efficiency. Furthermore, graphene based functional products such as heat spreader and heat sink developed for heat dissipation of electronic devices are also reviewed. Finally, the development and outlook for graphene based Cu composites are presented.