An inverse procedure to estimate the heat flux at coated tool-chip interface: a 3D transient thermal model

Abstract

Technological evolution has contributed to the production of increasingly efficient cutting tools, both from the point of view of the performance of these tools and regarding the increase in their life spans. Coating research and development has certainly played an important role in the advancement of these tools. The coatings facilitate cutting by friction through the action of tribological mechanisms, providing less tool wear and still thermally protecting the base material of the tools, acting as thermal insulators and increasing the tool life. However, because these coatings have a thickness on the order of micrometers, these thermal effects are difficult to prove. The main difficulty lies in identifying the heat delivered to a tool due to the friction at the piece-chip-tool interface. In addition, the complexity of a transient three-dimensional thermal model is added due to the two-layer materials (base-coating) with sizes on the order of centimeters and micrometers. In this sense, this work proposes an analytical solution to a 3D transient thermal problem that can model an orthogonal cutting process carried out by a coated cutting tool. The temperature field is obtained by using an inverse solution technique that estimates the heat flux delivered to the tool due to friction at the tool-piece interface. The inverse problem is solved by combining the analytical solution of the thermal model with the application of the transfer-function-based Green’s function (TFBGF) inverse technique.