Abstract
Abstract
While superhard cutting tools are being used increasingly in automotive plants worldwide, their adoption within the automotive supply chain is not universal. Important issues relating to successful implementation of superhard cutting tool materials in such applications include the ageing effect of grey iron, proper edge preparation of the cutting tools, and cutting conditions adopted. The paper examines quantitatively, the ageing effect on machinability of grey iron with polycrystalline cubic boron nitride (PCBN) cutting tools. The findings confirm that tool life increases with higher idle time after shakeout of the casting and the threshold period of 100 h is applicable to PCBN tools also. The benefits of using superhard cutting tools, including savings in increased uptime and cost per part and their impact on system costs, are considered in an illustrative case study. Here, it was found that imparting a wiper to the tool can beneficially increase tool life to the point of making PCBN economical to use over ceramic cutting tools and can result in relatively high savings for the plant.