Microstructure and mechanical properties of SiC-nanowire-augmented tungsten composites

Abstract

The effect of an addition of SiC nanowire on the microstructure and mechanical properties of tungsten-based composites is investigated in this study. SiC-nanowire-augmented tungsten composites were prepared by a spray-drying process and an in situ spark plasma sintering process. Three distinctive reaction phases, tungsten, tungsten carbide (W 2C) and rod-type tungsten silicide (W 5Si 3) were formed during the sintering process. The flexural strength was significantly increased from 706 MPa to 924 MPa in tungsten composites augmented with SiC nanowires, as was the formation of W 2C and W 5Si 3 phases. The rod-type W 5Si 3 bears significant stress by both sharing a portion of the load and providing a bridging mechanism. Furthermore, a high ablation resistance at an elevated temperature was observed for tungsten composites augmented with SiC nanowires.