Effects of Cr<SUB>3</SUB>C<SUB>2</SUB> and V<SUB>8</SUB>C<SUB>7</SUB> on the Microstructure and Mechanical Properties of WC-SiC Whisker Ceramics

Abstract

WC-SiC whisker ceramics (5 vol% SiC) containing Cr3C2 and/or V8C7 with no metallic binders were prepared by resistance-heated hot pressing at 1650°C and were examined with regard to sinterability, microstructure and mechanical properties. The addition of Cr3C2 or V8C7 brought about an increase or decrease in the sinterability. For equal molar amounts of Cr and V, V8C7 more strongly inhibited the growth of WC grains than Cr3C2. The hardness of the ceramics was dependent on the WC grain size which was influenced by the nature or quantity of the additives. The hardness values are consistent with the Hall-Petch-type relationship between hardness and WC grain size estimated for WC phases in WC-Co cemented carbides.