Copper Matrix Composites Synergetic Enhanced By Carbon Nanotubes And Alumina Particles And Basic Research Of Coating

Copper has excellent electric and thermal conductivity, and has good ductility and machinability. In addition, higher mechanical properties, friction lubrication performance, etc. are demanded by the material of electromagnetic cannon orbit, auto bearing and the piston rod. Therefore, this paper introduces copper matrix composites reinforced by carbon nanotubes (CNTs) owing excellent performance and wear-resisting alumina particles (Al2O3). We hope to get a kind of new copper matrix composite materials with outstanding performance, giving full play to their excellent properties of carbon nanotubes, alumina and copper, with the synergy effect of carbon nanotubes and alumina particles.Reinforcing phases are coated copper plating by electroless copper plating process, in order to improve the wettability between reinforcing phases and copper matrix and make them evenly distribute in the matrix. This paper studies the mechanical properties and physical properties of copper matrix containing different mass percentages of reinforcing phase undering different preparation processes. It provides the experimental data and lays the foundation for carbon nanotubes and alumina particles synergy mechanism. The synergy comes true in the mechanical properties and friction performance. Vickers hardness increases by67.2%. The rate of synergy increase is0.3%. Tensile strength increases by63.8%. The rate of synergy increase is18.8%. The wear rate decreases55.9%. The rate of synergy is35.0%. Electrical conductivity canb be maintained76.3%. The rate of synergy increase is15.8%. Thermal conductivity can be maintained76.4%. The rate of synergy increase is3.2%.We choose WC-12Co coating to meet actual demand and increase service life of copper matrix composites by high velocity oxygen fuel (HVOF) process. We test coating properties:surface hardness of coating is higher than cross section of coating. The hardness of junction between coating and substrate is311.80HV0.05, higher than the hardness of matrix. The bonding strength between coating and substrate is60-70MPa. The coating keeps in good condition after thermal shock resistance testing for46times. Wear rate is10-14-10-13m2·N-1order of magnitude and far lower than that of the matrix.We get the most suitable conditions for coating:speed is300-500r. min-1and load is2-3N. Friction way of coating are adhesive wear and abrasive wear. Wear rate first decreases and then increases with the speed increases. Wear rate increases with load increases. Friction coefficient first increases and then decreases with the speed increases. Electrical conductivity is2.69%IACS and poriness is2.8%.