Kazutaka Isobe

Material design method for the functionally graded cemented carbide tool

The aim of this study is to apply the concept of functionally graded materials (FGMs) to tool materials and to develop high-performance cutting tools. The requirement of the graded structure is that the surface is highly wear resistant cermet, and the inside is tough cemented carbide. Compressive residual stress was introduced to the material surface by grading the composition. To develop the new material, the cutting condition of broken cermet was investigated and their cutting temperature distribution was measured by a newly developed measuring method. Then Computer Aided Engineering (CAE) analysis was performed to calculate the generated thermal stress. The new material was developed with the aim to introduce the compressive residual stress over the calculated thermal stress. As a result developed tools demonstrated higher wear resistance, breakage resistance, thermal crack resistance and peeling resistance over those of conventional tools in the market.