Cemented carbide body with improved high temperature and thermomechanical properties.

摘要

According to the invention there is now provided a cemented carbide grade for rock excavation purposes with 96-88 % WC, preferably 95-91 wt-% WC with a binder phase consisting of only Co or Co and Ni, with maximum 25% of the binder being Ni, possibly with small additions of rare earth metals, for example Ce and Y, up to max 2% of the total cemented carbide. The WC grains are rounded because of the process of coating the WC with Co, and not recrystallized or showing grain growth or very sharp cornered grains like conventionally milled WC, thus giving the bodies according to the invention surprisingly high thermal conductivity. The average grain size should be 8-30 mu m, preferably 12-20 mu m. The maximum grain size does not exceed two times the average value and no more than 2 % of the grains found in the structure are less than half of the average grain size. IMAGE