Properties Of Copper Matrix Composites Research Articles

Effect of TiC Particles on the Properties of Copper Matrix Composites

Effect of TiC Particles on the Properties of Copper Matrix Composites

Enhanced mechanical and tribological properties of copper matrix composites reinforced by copper-coated graphite and Ti3AlC2

To solve the poor mechanical properties of graphite-reinforced copper matrix composite, the effect of Ti3AlC2 content on the mechanical properties and dry sliding properties of copper-coated graphite reinforced copper matrix composites was investigated. The results show that the in-situ TiCx-Ti3AlC2-Cu(Al) gradient interface is formed due to the decomposition of partial Ti3AlC2 particles, which can improve the interface bonding strength and enhance the mechanical properties of the composites. With the Ti3AlC2 content increasing, the hardness, yield strength, and tensile strength of the composites increase, while the elongation decreases. The composite reinforced by copper-coated graphite and 5 wt% Ti3AlC2 shows a higher yield strength and tensile strength, increased by 86.2% and 28.6% over the neat Cu, respectively. Besides, the composites exhibit better wear resistance compared with the neat Cu. The wear rate of the composites decreases as the increase of Ti3AlC2 content. The wear mechanism changes from delamination wear of pure Cu to adhesive wear, abrasive wear, and oxidative wear for the composites reinforced by copper-coated graphite and 10 wt% Ti3AlC2.

Microstructure and properties of copper matrix composites reinforced with Cu-doped graphene

Microstructure and properties of copper matrix composites reinforced with Cu-doped graphene

Tribo-electrical properties of copper matrix composites in salt-fog environment

To enhance the reliability of floating offshore wind platforms exposed to salt-fog environment, a new material, CNTs-MoS2/Cu, was developed for slip rings. Tribo-electrical properties of composites in salt-fog environment were explored. A novel method for characterizing current-carrying stability, based on correlation dimension, was proposed. When compared to copper, the correlation dimension decreased by 31.43%. It reveals that composites exhibit superior current-carrying stability compared to copper in salt-fog environment. The wear mechanism is further revealed. CNTs enhance the damage resistance of friction film, while MoS2 contributes lubrication. The appropriate addition of CNTs and MoS2 leads to the formation of an intact conductive lubrication anti-corrosion film on the surface, reducing the erosive impact of salt fog.

Microstructure and thermal properties of copper matrix composites reinforced by 3D carbon fiber networks

Three-dimensional (3D) carbon fiber (CF) networks were constructed by electrodeposition using Cu foam as template, and then 3D CF/Cu composites were prepared by hot pressing sintering. Experimental investigations revealed the successful formation of a well-connected 3D CF network embedded within the Cu matrix. The constructed 3D CF networks are conducive to establishing effective heat transfer channels in the composites. The thermal conductivity of the 3D CF/Cu composite with 20 vol% CF in the X–Y plane and Z plane are 418 ± 3 Wm−1K−1 and 415 ± 5 Wm−1K−1, respectively. The thermal conductivity of the composites is significantly enhanced, and the thermal conductivity becomes isotropic. Additionally, the construction of the 3D CF network promotes efficient heat transfer in CF/Cu composites, providing a promising strategy for the development of advanced CF/metal thermal management materials.

Tailoring the interface with the in-situ formed chromium oxide and carbide for higher mechanical properties of copper matrix composites

The weak interface is a key issue that needs to be addressed for the carbon nanotubes (CNTs) reinforced metal matrix composites. Herein, uniform and continuous Cr(OH)3 coating was firstly decorated on the surface of CNTs, and Cr(OH)3 coating was subsequently thermally decomposed into the Cr2O3 transition layer during the fabrication processes for the Cu matrix composite. It is found that the precoating Cr(OH)3 on CNTs can promote the dispersion of CNTs in the Cu matrix because the coating can reduce the density difference between CNTs and Cu powders. Meanwhile, the Cr2O3 transition layer has obvious constituent interaction with the Cu matrix, and in-situ nanosized Cr carbides (Cr2C3 and Cr23C6) form between the CNTs and Cr2O3 layer, forming a composite interface structure. Benefiting from the homogeneous dispersion of the decorated CNTs and enhanced interfacial bonding, the compression yield strength of the bulk composite reaches 383.5±21.0 MPa, showing a 217% and 147% increase over the pure Cu and the composite reinforced by uncoated CNTs, respectively. The substantially enhanced strength mainly derives from the strengthening mechanisms of Orowan looping and load transfer. The developed novel strategy paves a new route for interface regulation and strength improvement of other CNTs reinforced metal matrix composites.

Preparation and Properties of Copper-Based Composites Containing Nb1-x(Ti/Ta)xSe2

In this study, copper-based-Nb1-x(Ti/Ta)xSe2 composites were prepared by powder metallurgy, and Nb1-x(Ti/Ta)xSe2 copper-based composites with different Ti/Ta doping atomic fractions were studied. physical, electrical and tribological properties. Among them, the doping amount of Ti and Ta has an important influence on the properties of the composite material. The doping amount of Ti can improve the mechanical, electrical and tribological properties of copper matrix composites within a certain range, especially when the doping amount of Ti is At 10at.%, the copper matrix composites exhibited excellent tribological properties. The addition of Ta greatly improved the tribological properties of the composites, and with the increase of Ta doping content, the friction coefficient of the copper-based composites gradually decreased. The research shows that the copper-based Nb1-x(Ti/Ta)xSe2 composite is a very promising new composite material.

Effect of Structure of Carbonized Polymer Dot on the Mechanical and Electrical Properties of Copper Matrix Composites

Carbonized polymer dots (CPDs) have been paid a lot of attention by researchers because of their excellent properties due to their unique structure. However, few studies have researched the impact of the CPD structure on composite applications. Herein, CPD and heat-treated CPD (h-CPD) are used to fabricate a reinforced Cu matrix composite. There was a semi-coherent interface between h-CPD and Cu. However, functional groups and polymer chains of CPDs decomposed during heat treatment, weakening the mechanical and electrical properties of the composites. These findings show that CPD structural integrity is vital to composites.

Synergistic enhancing effect of tungsten-copper coated graphite flakes and aluminum nitride nanoparticles on microstructure, mechanical and thermal properties of copper matrix composites

Thermal management materials with high thermal conductivity (TC), adjustable coefficient of thermal expansion (CTE) and excellent mechanical properties have promising applications in the electronic packaging and high-power density equipment fields. In this work, we have developed a novel strategy for tungsten-copper coated graphite flakes and aluminum nitride nanoparticles reinforced copper matrix composites (GFs(W–Cu)/AlN/Cu composites) fabricated by vacuum hot-pressing sintering. Herein, tungsten-copper coated graphite flakes (GFs(W–Cu)) were prepared by impregnation reduction and ultrasonic-assisted electroless plating, in which W–Cu coating improved interfacial bonding and realized metallurgical-physical synergy. Meanwhile, the AlN nanoparticles reinforced Cu flakes (AlN/Cu) were prepared by high energy ball milling, where AlN nanoparticles were evenly dispersed in the Cu matrix and played the role of pinning boundary and refining grain. Effects of nano-AlN with different volume fractions on the mechanical and thermal properties of GFs(W–Cu)/AlN/Cu composites were studied as well. As for the mechanical properties, the in-plane, through-plane flexural strength and tensile strength of GFs(W–Cu)/1.5AlN/Cu composite reached 276.7 ± 4.5, 390.6 ± 4.5 and 136.1 ± 3.0 MPa respectively, which increased by 96.8%, 283.7% and 120.7% than those of the GFs(W–Cu)/Cu composites. In terms of the thermal properties, the in-plane TC of GFs(W–Cu)/1.5AlN/Cu composite is 617.8 ± 12 Wm−1K−1, while the through-plane CTE ranging 25–200 °C is 4.9 ± 0.2 ppmK-1. In conclusion, the GFs(W–Cu)/AlN/Cu composites provide a huge potential for design and application in the thermal management materials.

Preparation and properties of copper matrix composites synergistically strengthened by Al2O3 and CPD

The development of copper-based composite materials is increasingly requiring both high electrical conductivity and better mechanical properties. In this paper, a novel copper-based composite was prepared by combining carbonized polymer dot (CPD) with flake copper powder (BMCu) and Al2O3 with molecular-level copper powder (MLCu). The composite obtained good mechanical properties with the yield strength of 157.00 MPa and the tensile strength of 366.14 MPa, which are increased by 17.4% and 25.1% compared with those of pure copper matrix (133.76 MPa and 292.72 MPa). The hardness of the composite is 124.7 HV, 27.4% higher than that of pure copper (97.9 HV), and the conductivity is 93.15% IACS. Besides, the strengthening mechanism of tensile property is also discussed, and the improvement of composite strength is mainly due to the dislocation strengthening. This study provides a new idea for the preparation of copper-based composite materials with high electrical conductivity and mechanical properties.

In-situ generated graphene from wheat flour for enhancing mechanical and electrical properties of copper matrix composites

Graphene, with its excellent mechanical properties and electrical conductivity, has been considered as an effective reinforcement phase for copper matrix composites. However, due to its easy agglomeration and poor wetting properties in the copper matrix, it is difficult to simultaneously enhance strength, ductility and conductivity of graphene matrix copper composites using a low cost and efficient method. In this paper, we proposed a new methodology to use wheat flour as a solid carbon source to in-situ generate graphene-coated copper (Gr@Cu) composite powders. These powders were then used as strengthening phases to fabricate Gr@Cu copper composites through wet mixing and spark plasma sintering (SPS) processes. Results showed that not only high-quality graphene layer was obtained and serious agglomeration of graphene was avoided, but also a strong interfacial bonding between graphene and copper matrix was achieved. The fabricated composites showed excellent properties, e.g., a maximum density of 99%, enhanced micro-hardness (15%–22% higher than that of pure copper), and excellent strength/ductility. The maximum tensile strength and yield strength were obtained in the 0.70 wt.%Gr@Cu/Cu composites (e.g., 252 MPa and 132 MPa, respectively). These values are ∼23% and ∼110% higher than those of pure copper, and the elongation rate was maintained at ∼30%. In addition, the composites showed excellent conductivity.

Effect of type and content of iron powder on the formation of oxidized film and tribological properties of Cu-matrix composites

This paper studied the effects of iron powder types and contents on the friction and wear properties of copper matrix composites for breaking of high-speed trains. The mechanical properties, microstructure, interface, tribofilm, elements and microhardness of samples were analyzed by hardness tester, SEM, EDS and nanoindentation tests. The braking performances were measured by a tribometer mimicking the braking conditions. The results show that the wettability and combination between ferrophosphorus and matrix is poor and carbonyl iron is more suitable for strengthening matrix. The friction coefficient is most stable and the wear rate is also relatively low with 10% carbonyl iron. The increase of carbonyl iron content will promote oxidation and be conducive to the formation of friction film. The oxide degree of friction film increases in the direction from the matrix to the surface. However, too much iron powder produces excessive iron oxide which makes the friction film be easy to peel off especially under high speeds.

Friction and Wear Properties of Copper Matrix Composites with CNTs/Cu Composite Foams as Reinforcing Skeletons

Friction and Wear Properties of Copper Matrix Composites with CNTs/Cu Composite Foams as Reinforcing Skeletons

Lateral size effect of reduced graphene oxide on properties of copper matrix composites

Graphene/copper composite using graphene oxide sheets with three kinds of lateral sizes (~0.92 μm, ~5.49 μm and ~13.73 μm) were prepared via molecular level mixing method and spark plasma sintering process. The lateral size effects of graphene on the structure, mechanical performance, thermal and electrical conductivities of the composites were investigated while the volume fraction of graphene remained 2.5 vol%. For microstructure, small-sized graphene sheets (denoted as SRGO) tend to distribute randomly in the composites while middle-sized (denoted as MRGO) and large-sized graphene sheets (denoted as LRGO) are prone to form the carbon-rich aggregate with micro-layered structure. MRGO/Cu composite has the highest tensile yield strength (663 MPa) while SRGO/Cu composite exhibits the most excellent thermal and electrical conductivities (334 W/(m × K), 82 %IACS) among the three composites. This work provides a better understanding the formation mechanism of hierarchical layered graphene/Cu composite and can further promote the development of architectural design of graphene based composites.

Employment of Micro- and Nano-WS2 Structures to Enhance the Tribological Properties of Copper Matrix Composites

Friction and wear are responsible for around 23% of the energy consumption in transportation, manufacturing, power generation, and residential sectors. Employed components are exposed to a wide range of operational conditions, therefore a suitable material design is fundamental to decreasing tribological issues, energy consumption, costs, and environmental impact. This study aims to analyze the effect of different solid lubricants on the suitability of copper matrix composites (CuMCs) as a potential solution to reduce the depletion of sliding electrical contacts working under extreme conditions. CuMCs samples are produced by cold-pressing and sintering to merge a high electrical conductivity with the lubricant effect supplied by different species, namely tungsten disulfide micro-powder (WS2), inorganic fullerene-like (IF) tungsten disulfide nanoparticles, and graphene nanoplatelets (GNP). The crystalline structure of the pristine and composite materials is characterized via XRD. The electrical tests show a small decrease of conductivity compared to pure copper, due to the insulating effect of WS2; however, the measured values are still adequate for conduction purposes. Micro-scratch and wear tests highlight the positive effect of the combination of WS2 structures and GNP. The friction coefficient reduction leads to the possibility of extending the lifetime of the components.

Effect of Tribological Properties on Boron Carbide and CNT Reinforced Copper based Composites

The study focuses on the influence and contribution of multi-walled Carbon-Nano tube (MWCNT) and boron carbide (B4C) to the tribological properties of copper matrix composites. The Samples are prepared using ultrasonic assisted stir casting for different weight fractions. The tribological properties like wear and corrosion studies been carried out according to ASTM standards. Wear rate increased with the increase in speed and load for every combination of the composite. However, with CNT being the main reinforcement with addition of CNT wear rate has reduced marginally. Addition of Boron Carbide also to some extent decreased the wear rate but CNT plays a major role in reducing the wear rate. Corrosion studies of the composite materials is carried out by Weight loss corrosion techniques, it is clearly evident from the critical analysis of the results that with the addition of reinforcements to the composite material, the corrosion rate in weight loss corrosion technique decreases drastically with the duration of time, this is due to the formation of a passive oxide layer on the composite specimen.

Graphene-like carbon nanosheet/copper composite with combined performance designed by pyrolyzing trimesic acid@copper formate

Abstract Graphene or graphene-like carbon nanosheet (GNS) with excellent properties presents great potential to improve substantially the combined properties of copper matrix composites. However, it is still a great challenge to develop new methods for the preparation of GNS-reinforced copper composites. In this work, high-strength, high-conductivity and low-thermal expansion GNS/Cu composites were prepared by pyrolyzing trimesic acid@copper formate and spark plasma sintering. Both the volume fraction and the order degree of carbon in GNS/Cu composites were improved by the introduction of trimesic acid. The highest tensile and compressive yield strength of GNS/Cu composites are 542 MPa and 637 MPa, respectively. After hot-rolling process, the plastic deformation and the electrical conductivity of the composites are improved effectively and reach 9% and 86.2% IACS, respectively; the average coefficient of thermal expansion (CTE) of the composite is as low as 12.4 × 10−6 °C−1, which is only 72.9% of pure Cu material. This work provides an effective solution for the design of the GNS/Cu composites with excellent combined performance.

Composite structural modeling and mechanical behavior of whisker reinforced Cu matrix composites

To study the effect of TiB whisker on the mechanical properties of copper matrix composites (CMCs), a 3D microscopic TiB/Cu finite element model was established. By using the geometric features of TiB whisker obtained from the scanning electron microscopes (SEM), random dispersions of the length, the diameter, the positions and the volume fractions of TiB whiskers were numerically reconstructed in line with their actual microscopic structures. Brittle fractures of whisker, ductile damage and failure behaviors of matrix, and whisker–matrix interfacial behaviors are introduced in the model to simulate the mechanical behavior of TiB/Cu. The results show that when the length of TiB whisker exceeds 6d, the tensile strength of TiB/Cu tend to be stable at 320 MPa and the elongation tend to be stable at 0.086, where d is the diameter of TiB whisker. The effective length of whisker in TiB/Cu is 6d. Damage mechanisms in TiB/Cu were revealed by analyzing the average stress in the end and the middle of TiB whisker, and the simulation results were consistent with the experimental observations. This work provides a theoretical basis for the selection and optimization of parameters of reinforcement phase in preparation of TiB/Cu.

Preparation and Mechanical Properties of Copper Matrix Composites Reinforced by Carbon Nanotubes and Al2O3

CNTs/Cu‐Al2O3 composites are successfully prepared by internal oxidation, chemical vapor deposition and spark plasma sintering (SPS) method. The influence of Al content (0.12 and 0.6 wt%) on the morphology of grown carbon nanotubes and the mechanical properties of composites are systematically studied. The results show that under the same growth process, more carbon nanotubes are obtained on the surface of the powders with 0.6 wt% Al content. The CNTs/Cu‐Al2O3 composites with 0.12 wt% Al content displays higher mechanical properties, the tensile strength is 280 MPa, and the micro‐hardness is 123.3 HV, which is increased by 40.7 and 78.2% in contrast with that of pure copper, respectively. Moreover, the electrical conductivity of CNTs/Cu‐Al2O3 (Al content is 0.12 wt%) composites is still at the high level of 83.2% IACS. This work uses chemical vapor deposition to improve the dispersion and interfacial bonding of CNTs in the matrix and increase the properties of the composites, which provides a new idea for the preparation of high strength metal matrix composites.

Effect of reduced graphene oxides decorated by Ag and Ce on mechanical properties and electrical conductivity of copper matrix composites

This work investigated the influence of reduced graphene oxide (rGO) modified with silver (Ag) and cerium (Ce) on mechanical and electrical properties of copper matrix composites. Powders of Ce doped rGO and Ag doped rGO were synthesized using a hydrothermal reduction and an electroless plating (glucose chemical reduction) method, respectively. Then, composites with rGO content of 0.25 wt% were synthesized using ball milling and spark plasma sintering (SPS). The dispersion of the modified rGO and its bonding with the copper matrix have been signficantly improved. Hardness values of Ce-rGO/Cu and Ag-rGO/Cu composites were 26.3% and 16.4% higher than those of the sintered copper, and 19.4% and 10% higher than that of unmodified rGO/Cu composite. Meanwhile, the Ce-rGO/Cu and Ag-rGO/Cu composites maintained good conductivity and high ductility (with elongations of 26.3% and 25.2%, respectively). Compared with the sintered copper, the tensile strengths of these two types of copper matrix composites were 7.5% and 12% lower, respectively. The increase in hardness by using the modified rGOs is mainly due to the grain refinement of the matrix, and the lower value of the tensile strength is due to the defects of the modified rGOs and their poor bonding with the copper matrix.