CEMENTED CARBIDE AND PROCESS FOR PRODUCING THE SAME

摘要

The present invention relates to a cemented carbide comprising WC grains, 3-20 wt. % binder selected from Co or Co and Ni and grain growth inhibitors wherein the WC mean grain size lies in the range of 180 nm and 230 nm, at least 10±2% WC grains are finer than 50 nm and 7±2% WC grains have a size from 50 to 100 nm. The invention further relates to a process for production the cemented carbide including the stages of milling WC powder with specific surface area (BET) of 3.0 m2/g or higher with binder and grain-growth inhibitors; pressing green parts; pre-sintering the green parts in H2 at 400° C. to 900° C. for 5 to 30 min; sintering in vacuum at temperatures of 1340° C. to 1410° C. for 3 min to 20 min; and HIP-sintering in Ar at pressures of 40 to 100 bar at temperatures of 1340° C. to 1410° C. for 1 to 20 min