Abstract
The evaluation of undesirable failure of carbide tool material was conducted by use of heavily-loaded cross-pin-type friction test. If difficult-to-cut material which has highly work-hardening tendency is used as work material, instable wedge formation occurs depending only on the PV-value. In lower and higher PV regions, stable friction occurs and smooth migration layer from the work to the tool is formed. On the other hand, in middle PV region, instable friction occurs and detachment or peeling-off of work migration layer is observed. It is found that the tool material failure occurs if the normal load is large in the instable region. It is considered that the occurrence of the tool material failure depends on the magnitude of critical load of crack propagation taking account of surface roughness.
