Empirical model for room temperature thermal conductivity of WC-Co hardmetals

Hardmetals or cemented carbides are a widely used material for cutting tools due to their excellent mechanical properties. However, the tool’s ability to transfer heat, which is defined by the thermal conductivity, is also of high importance in view of the high temperatures which occur during metal cutting. In this work the measured thermal conductivity of various WC-Co hardmetals is correlated with the metallic binder content, which ranged between 5 wt% and 20 wt%, and the WC grain size, which was measured using linear intercept analysis and ranged between 0.1 µm and 2.4 µm. An empirical model to estimate the room temperature thermal conductivity of WC-Co hardmetals as a function of WC grain size and Co content is proposed and discussed.