The Study On Preparation And Properties Of Aluminum Matrix Composites Reinforced By Short Carbon Fiber

Carbon fiber (Cf) is a low density material with high temperature resistance, good corrosion resistance and high strength. Carbon fibers reinforced metal matrix composites not only has a low density, good strength and abrasion resistance, but also excellent electrical conductivity, thermal resistance, fatigue resistance, electromagnetic shielding characteristics. Thus, it is widely used in the automotive, rail transportation, aerospace and other fields.In this paper, short carbon fibers reinforced aluminum matrix composites with a higher density were prepared by powder metallurgy technology. For increasing the interface wettability and inhibiting interfacial reactions between aluminum matrix and carbon fiber, the carbon fibers were coated copper by plating and the process were optimized. The preparation process, microstructure, mechanical properties and tribological properties of the composites were studied. The results showed that:When short carbon fibers are electroless copper plating with electric mode stirring, The optimized composites of the plating bath are: CuSO415g/L, Potassium sodium tartrate20g/L, EDTA25g/L, NaOH16g/L, HCHO15ml/L,2,2’-bipyridine6mg/L, potassium ferrocyanide20mg/L. The temperature is setting at45℃, pH12.5, the Cf3g. The volume of the bath is1000ml. Copper layer crystallized Well and polycrystalline Cu plating is composed of different oriented Cu grain. Its thickness is about1μm.The additions of carbon fibers have significant effects on density, hardness and wear properties of composites. Composites’ density gradually decreases with the increase of Cf in the volume fraction. The addition of carbon fibers and artificial aging treatments increase the hardness of composites. The hardness of composites with5%carbon fibers reaches the maximum (68.4HV before aging,110.3HV after aging respectively). The wear weightlessness of composites with5%carbon fibers reaches the minimum (0.2476g before aging,0.1089g after aging respectively).Analysis indicates that the main wear mechanisms of pure aluminum and magnesium matrix composites are adhesive wear and plastic deformation. By contrast, the main wear mechanisms of carbon fiber reinforced aluminum and magnesium composites are slight adhesive wear and abrasive wear. Furthermore, the reinforced wear mechanism of carbon fiber in composites is ascribed to constrain base shape change and shift load.