Study On Fabrication And Tribological Property Of SiC Whisker Modified WC Matrix Composites

Cemented carbide was used widely in the field of cutting tool because of itsexcellent hardness, wear-resistant performance,flexural strength，heat resistance and aseries of excellent properties. Especially it still have high hardness and wearresistance at500℃temperature, and still have very high hardness at1000℃.Thecontradiction between hardness and toughness restricts further application areas ofit．It is difficult to meet the development of modern social on the double high require，namely high hardness and high toughness．A lot of researchers around the world aretrying to looking for effective ways to solve the problem in the cemented carbide. Forexample, super fine and nano cemented carbide, lamellae toughened cementedcarbide, graded cemented carbide, etc. However, few researcher to solve the problemby adding SiC whisker..The study progress and developmental trend of cemented carbide and SiCwhisker have been reviewed, and the basic theory of tribology have also beensummarized. Conventional homogeneous cemented carbide with homogeneouscomposition and microstructure in bulk has sharp contradiction between hardness andtoughness. Based on this problem, the purpose of the dissertation is to obtaincomprehensive delicate mechanical properties of composite materials by adding SiCwhisker.With SiC whiskers as the toughing materials, made use of cobalt felt phase asadditive, the new-style SiC whisker toughing WC-based composites cutting werebeen fabricated by hot-pressing sintering method in hot pressing sintering.Theoretical analysis of the composite material composition, preparation methods, etc.;At the same time the SiC whisker was studied and hot pressing sintering process onthe properties of the density of modified composite material and various (hardness,bending strength and fracture toughness), the influence of sintering process wasoptimized.Finally, The tribological behaviors of composites were evaluated. Thefriction and wear behaviors under dryffiction influence of different contents of SiCwhisker and different loads to the composites were researched at last. At the sametime，The morphologles of the wear traces were observed by scanning electronmicroscopy for the research of the mechanism of wear.Finally, the summary of research content was made and the problem and prospect of SiCwhisker modified WC-based composites was presented in this paper.