Effect of Sintering Temperature on Properties of SiC Fiber Reinforced Tungsten Matrix Composites

抄録

Continuous SiC fibers were used to toughen tungsten in this work. The composites were prepared by hot-press using W powders sintered from 1500°C to 1900°C for 1 h with 20 MPa pressure. Phases changes, microstructure, mechanical and thermal properties of composites were examined. Besides, the kinetics between SiC and W was also studied. The stress-strain curve had pseudo-ductility at room temperature, except for 1900°C sintered samples due to complete damage of fiber. Thermal conductivity was calculated from two directions: in-plane and through-plane directions (parallel and vertical to fiber direction), in which through-plane direction display higher thermal conductivity than other direction. Besides, severe reaction was verified between SiC and W, and the reaction rate increased 18 times when temperature increased from 1500°C to 1700°C. Therefore, it is suitable to use SiC fiber to reinforce W to ameliorate the brittleness with limited reaction between fiber and matrix.

Fig. 5 Results of tensile tests of SiC_f/W composites and pure W. Images (a) to (d) show the strain-stress curve of composites sintered from 1500°C to 1900°C respectively; Image (e) shows tensile test result of pure W sintered at 1700°C.