摘要
In this study,grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers(Vr=0.95%,1.90%,2.85%,3.80%)were investigated in as-cast and under the heat treatment temperatures of 1,000℃and 1,100℃.The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM,micro-hardness tester and three-point bend testing.The results show that with increasing of the volume fraction of tungsten fibers,the composites reinforced by the tungsten fiber have higher flexural strength and modulus than that of cast iron without reinforcement,and the flexural strength increases with the increasing of heat treatment temperatures.Due to diffusion reaction between matrix and reinforcing phases,the process of heat treatment,the number of graphite flakes in the matrix seemingly becomes lower;and some hard carbide particles are formed around the residual tungsten fibers.Not only does the hardness of both matrix and reinforcement change tremendously,but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.
In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers （Vr = 0.95 %, 1.90 %, 2.85 %, 3.80 %） were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher flexural strength and modulus than that of cast iron without reinforcement, and the flexural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite flakes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fibers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.
基金
supported by the Key Innovation Plan in Science & Technology,Shaanxi Province,China(Project No.2004ZKC05-02)
the Research Center for"13115"Innovation Engineering in Science & Technology,Shaanxi Province,China(Project No.2007ZDGC-17)
