The effect of thermal property degradation on wear of WC-CO inserts in dry cutting

Abstract

This paper investigates the relationship between wear and the conditions of heat removal at the tip of the tool. In this work we team numerical simulations to SEM imagery in order to map the thermal conductivity within the tool zone of action of a coated carbide (WC-CO) tool. The results indicate that depending on the temperature rise, the tool tip might undergo a severe drop in thermal conduction. This drop may locally restrict the ability of the tool material to dissipate the applied thermal load. This may nucleate thermally congested clusters within the tool tip where the material completely loses the ability to transport heat. The constriction of thermal transport renders an energetically active zone where the thermal energy available may be used to activate wear through different mechanisms. It is also found that the immediate layer under the surface of the tool tip is important to enhance the ability of the tool material to dissipate the thermal loads. The results highlight the importance of enhancing the efficiency of heat removal within the tool active zone in order to improve wear resistance.