Abstract
In this paper, the synthesis of WC-Co alloy was investigated. Especially the formation of WC phase during the solid-phase sintering was discussed. The chemical composition of WC-Co was chosen to be WC-20vol%Co. The powder mixture of stoichiometric quantities of elemental powders was mechanical alloyed by using low-energy ball mill under an Ar atmosphere. After 1800ks milling, the X-ray diffraction profile showed only elemental W phase. At DTA runs, W2C and Co6W6C phase formed about 1140K and then transformed to WC and W3Co3C with increasing temperature. Therefore, it is considered that the WC phase synthesized at the sintering process, not milling stage like other investigations. 1800ks milled powder was consolidated by using pulse current sintering method at the temperature of 1373K. The compact consisted mainly of WC with Co and W3Co3C phases. The hardness of the compact was 1648HV and 91.8HRA. The 3-point bending strength was about 2GPa.
