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

Continuous SiC fibers were used to toughen tungsten in this work. The composites were prepared by hot-press using W powders sintered from 1500 degrees C to 1900 degrees 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 degrees 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 degrees C to 1700 degrees C. Therefore, it is suitable to use SiC fiber to reinforce W to ameliorate the brittleness with limited reaction between fiber and matrix.

Automated summary

Continuous SiC fibers were used to reinforce tungsten in this study. The composites were prepared by hot-pressing technique. The reaction between SiC and W was severe and the thermal conductivity in the through-plane direction was higher.