Study And Preparation Of W-cu Composites Reinforced By Film Coated Carbon Fiber, Sic Fiber And Sic Whisker

W-Cu composites exhibit excellent physical and mechanical properties such as high strength and hardness, high thermal and electrical conductivity, low heat expansion coefficient, corrosion and oxidation resistance, good machining property and weld performance. W-Cu materials have been widely used for heavy-duty electronic contacts and heat sink materials for high-power microelectronic devices because of the high electrical conductivity of Cu and high ablation resistance of W.The essential point of this research is to research the mechanism of fiber/ whisker reinforcement and manufacture excellent W-20Cu composites by optimizing its processing or controlling parameter. In this study, aqueous solution composed of ammonium metatungstate and copper nitrate were used as the starting material, by spray drying of aqueous salt solutions and a milling process followed by reduction of the oxide powder. Ti-coated carbon fiber (Cf), Ti-coated SiC whisker (SiCw), TiN-coated SiC fiber (SiCf) by vacuum slow vapor deposition and W-20Cu composite powder prepared by spray drying & calcining-continuous reduction technology were mixed by ball-milling in ethanol solution, respectively. Hot-press sintering and spark plasma sintering (SPS) was used to prepare the W-20Cu composites, respectively. The results are showed as follows:1) W-20Cu composites reinforced by 0.6wt.% Ti-coated SiCw prepared by hot-press sintering with transverse rupture strength (TRS) of 1197MPa, thermal conductivity (TC) of 220 W·m-1·K-1 and relative density of 99.1% were obtained.2) W-20Cu composites reinforced by 0.8wt.% TiN-coated SiCf prepared by SPS with TRS of 1200MPa, TC of 235 W·m-1·K-1 and relative density of 98.5% were obtained.3) W-20Cu composites reinforced by 1.0wt.% Ti-coated Cf prepared by SPS with TC of 224 W·m-1·K-1, relative density 98.5% and TRS 1061 MPa were obtained.4) The TRS and TC of the 0.6 wt.% Ti-coated SiCw/W-20Cu composites, compared with the monolithic W-20Cu alloy, were enhanced 49.6% and 22.2%, respectively. The TRS and TC of the 0.8 wt.% TiN-coated SiCf/W-20Cu composites, compared with the monolithic W-20Cu alloy, were enhanced 50% and 30.6%, respectively. The TRS and TC of the 1.0 wt.% Ti-coated Cf/W-20Cu composites, compared with the monolithic W-20Cu alloy, were enhanced 32.6% and 24.4%, respectively.These results provide instructive attempts of the surface treatment of SiCw, Cf and SiCf and the application in W-Cu composites. The main conclusions of this research provide many experimental foundations and bases for the industrialization and widely uses of high quality tungsten-copper composites.