Advanced tool edge geometry for high precision hard turning

The hard turning process has been attracting interest in different industrial sectors for finishing operations of hard materials. However, it still presents disadvantages with respect to process capability and reliability. In this paper the impact of PcBN tool edge geometry is investigated based on a modelling as well as an experimental approach. The hard turning process is described by means of a 3D simulation of the tool engagement based on the Finite Element Method. The simulation results indicate force and temperature distribution in the tool-chip contact zone for different designs of PcBN tool cutting edge, thus allowing the derivation of criteria for an advanced tool edge design. The recommendations for tool edge geometry modification are experimentally verified. The results suggest that the use of the proposed new tool edge geometry is an effective way to significantly increase tool performance with respect to tool life, material removal rate and part surface quality in high precision hard turning.