| In recent years, WCp/steel (iron) matrix composite material is widely concentrated due to its advantages and this kind of material has made a progress in application. However, there are thermal physical characteristic differences between the body of the material and the particles of WC. Hence, materials will generate thermal stress and thus result in cracks which will lead materials loosing efficacy. It is greatly important to study on the thermophysical properties of the material. The organizational structures of previous studies about this material are rather complicated, which result in a more complicated way to research mechanics and thermophysical properties, and fail to study on the correlative mechanism of the mechanics and thermophysical properties which are influenced by composite parameters belonging to the material. This article focuses on this problem and thus puts forward new preparation method in order to produce composites material which is unique and the process is under control. Particles of WC are equally distributed. This article investigates the impact of the size of WC particles, volume fraction, particle shape and different raw materials to composite material structures, the interface, mechanics along with thermophysical properties, excludes influences from other factors towards composite material, researches one single factor, and provides the basis for producing and planning composite materials.The research result shows:the mechanical property of the WCp/steel (iron) matrix composite material rises along with the increase of the volume fraction of WC. As the volume fraction is 30%, the compression performance and hardness of the material are the best. As the volume fraction keeps increase, the mechanical property will decrease instead of going up. WC is difficult to melt in cast tungsten carbide. W2C is easily melt. As the melting W2C and Fe powder react to Fe3W3C. As the mixed powder of tungsten carbide particles and Fe powder react over their melting points, the width of the interface does not change a lot. However, under their melting points, the width of the interface becomes wider along with the temperature going up. Compared 1 with irregular tungsten carbide particles, sphere particles possesses excellent compression performance and hardness. Composite materials of ferritc materials are better than pearlitic ones in compression performance and hardness. The form, distribution and quantity of the resultant Fe3W3C have close relationship with mechanical property. As Fe3W3C continuously appears among tungsten carbide particles with bigger width, WCp/steel (iron)-based composite material get better compression performance and hardness. As the volume ratio of the resultant Fe3W3C and tungsten carbide particles is 1:1, WCp/steel (iron) matrix composite material get bettercompression performance and hardness as well.The thermal conductivity of the composite material first increases and then decreases along with the decrease of the size of tungsten carbide particles; as the size is 150-180μm, the material get higher conductivity. As the quantity of the volume of tungsten carbide particles goes up, the conductivity of the composite material goes down. As the size of the volume keeps steady, the conductivity of irregular tungsten carbide particles composite material is lower than sphere tungsten carbide composite material. The conductivity of composite materials of ferritc materials is better than pearlitic ones. The composite material with particle sizes between 250-380μm possesses higher coefficient of thermal expansion than the material with particle sizes between 550-830μm. As the temperature rises, the conductivity rises as well. As particle sizes are 150μm～180μm, the conductivity decreases along with the increase of the temperature. |
PDF Full Text Request