Abstract
Cr-Carbides (SiC, WC and TiC) composites were prepared by HIP technique. Although the chromium is easy to react with the carbides at high temperature, the fractions of reactions were controlled below 27% at 800°C using the carbide powders having large grain sizes of 25-110 μm. The dense and pore free composites with the compositions of Cr-5 wt% Carbide and Cr-10 wt%SiC, 20 wt%WC, 10 wt%TiC were obtained at 800°C (at 900°C for Cr-TiC) for 30 min, applying 50-200 MPa and 200 MPa, respectively. The thickness of reaction layers around SiC, WC and TiC grains were measured to be about 5.3 μm, 5.8 μm and 2.8 μm, respectively. In the Cr-WC composite, the growth rate of the reaction layer largely decreased with an increase in HIPing pressure. The activation volume of the reaction was calculated as 80 ml/mol, which is larger than that of metalmetal composite. The Cr-Carbide composites exhibited excellent wear resistances, which were also increased under higher HIPing pressure.
