Mechanical, electrical and thermal properties at elevated temperature of W-Si-C multi-phase composite prepared by arc-melting

摘要

In this research, the high-temperature mechanical, electrical and thermal properties of arc-melted W-based composites with a small amount of SiC additives were investigated. The high-temperature mechanical properties of tungsten were enhanced by the presence of the hard ceramic phase (W5Si3 and W2C) and the interaction of dislocations. The ceramic phase also played a role in inhibiting the grain growth at high temperatures. The ultimate compressive strength (UCS) of the W with 1 wt% SiC (S1) was 968.9 MPa at 1273 K, which is three times that of pure W (291.9 MPa) at 1273 K, showing a significant enhancement in high-temperature strength. Both thermal conductivity (kappa) and electrical conductivity (sigma) decreased with the increasing of SiC addition. With increasing temperature, the sigma decreased while the kappa increased due to the intrinsic behavior of the ceramic phase in the composites.