Study On Preparation And Properties Of C-Cu Composites Reinforced With Carbon Fiber Cloth

Traditional C-Cu composites gradually can’t satisfy the increasingly stringent requirements of rapidly developmental transportation and modern industry, and the addition of carbon fiber can greatly improve mechanical properties and wear resistance of composites. At present, the studies on preparation and properties of laminated C-Cu composites reinforced with carbon fiber cloth by hot pressing and sintering preparation have not been reported. In this paper, C-Cu composites reinforced with carbon fiber cloth were prepared by electroplating and hot pressing. Effects of hot pressing process on the microstructure and mechanical properties were studied, and the influences of related factors on friction and wear properties and wear mechanism were also discussed.In order to improve the wettability between carbon fiber cloth and copper, carbon fiber cloth was copper coated by electroplating, and their surface morphologies were analyzed. The results show that carbon fiber cloth is copper coated well when electroplating time is about1.5h. The coating grain becomes large and pores begin to appear on the surface with the extension of plating time.Through analyzing the microstructure and mechanical properties of composites, it is shown that the organization is more homogeneous, and carbon fiber and graphite scatter evenly in copper matrix when hot pressing condition is1000℃x0.5h. Higher or lower sintering temperature and extension of holding time all can affect the uniformity of organization. With increasing of sintering temperature, the density, hardness, bending strength and shear strength of composites all increase at first and then decrease, and reach the maximum at1000℃. On the basis of0.5h, increasing of holding time weakens mechanical performances. When hot pressing condition is1000℃x0.5h, the relative density, hardness, bending strength, shear strength of composites are96.8%,81HB,109.9MPa,70MPa, respectively.The wear test of composites and copper ring was conducted under dry friction condition. Through analyzing the morphologies and phase composition of worn surfaces, the friction and wear properties and mechanism were studied under various influencing factors. The results show that wear resistance of composites is best when the friction orientation parallel to the textures, and slight adhesive wear and abrasive wear are the main wear mechanism. With increasing of sintering temperature, friction coefficient and wear rate of composites decrease at first and then increase, and reach the minimum at1000℃. On the basis of0.5h, the extension of holding time makes friction coefficient and wear rate increase. As the load increase, friction coefficient and abrasion loss increase and the main wear mechanism is transformed from slight adhesive wear into delamination wear and is accompanied by particle attrition and slight oxidative wear at the same time. With increasing of sliding velocity, friction coefficient increases, but wear rate decreases firstly and then increases, and the main wear mechanism is transformed from slight adhesive wear into delamination wear and is accompanied by slight oxidative wear. Compared with steel ring, the friction coefficient and abrasion loss of composites are larger because of adhesive wear when paired with copper ring. The average friction coefficient and wear rate of composites reduce after continuous and long wear, and compared with steel ring, the average friction coefficient and abrasion loss of composites are still larger when paired with copper ring.