Low‐Temperature Spark Plasma Sintering of Pure Nano <scp>WC</scp> Powder

Abstract

For the first time we have demonstrated the densification of high‐purity nanostructured (d avg ≈ 60 nm) tungsten carbide by High Pressure Spark Plasma Sintering ( HPSPS ) in the unusually low temperature range of 1200°C–1400°C. The high‐pressure sintering (i.e., 300 MPa) produced dense material at a temperature as low as 1400°C. In comparison with more conventional sintering techniques, such as SPS (80 MPa) or hot isostatic pressing, HPSPS lowered the temperature required for full densification by 400°C–500°C. High Pressure Spark Plasma Sintering, even in absence of any sintering aid or grain growth inhibitor, retained a very fine microstructure resulting in a significant improvement in both hardness (2721 HV 10 ) and fracture toughness (7.2 MPa m 1/2 ).