Temperature distribution of cubic boron nitride–coated cutting tools by finite element analysis

Abstract

Heat generation in cutting process has a great influence on performance and lifetime of cutting tools. Cubic boron nitride (cBN), combination of exceptional thermal conductivity and hardness, is a promising super-hard material as protective coatings on the cutting tools. However, the temperature distributions of micron-thickness coatings on cutting tools are very difficult to be examined by experiment methods. In this paper, finite element method (FEM) simulation was introduced to determine the temperature distribution of cBN/diamond coatings on silicon nitride (Si3N4) cutting tools with various parameters compared with titanium aluminum nitride (TiAlN) coatings. The finite element (FE) model of cBN/diamond–coated Si3N4 tools was built and validated by machining experiments. The effects of cutting speed and tool rake angle on temperature distribution of cBN/diamond–coated tools were investigated compared to TiAlN coatings based on developed model. The results show that the temperature is increased with the increase of cutting speed while decreased with the increase of tool rake angle. The temperature of cBN-coated tools is decreased by approximately 20.4–28.6% than TiAlN-coated tools under identical conditions. Additionally, the preferred cutting speed and rake angle were obtained among employed cutting parameters. The results demonstrated that using advanced cBN coatings can substantially improve the cutting performance of the tools. This work may offer a guideline to explore the temperature distribution of cBN-coated cutting tools in mechanical machining application for machining difficult-to-cut ferrous materials.