An Inverse Method for Investigating Deformation Zone Temperatures in Metal Cutting

A major obstacle in verifying metal cutting temperature models and including thermal variables in empirical studies is the experimental difficulty of measuring physically meaningful cutting temperatures. This is especially true for deformation or shear zone temperatures, which influence the mechanical properties of the work material. This paper describes an inverse method for investigating deformation zone temperatures in end turning tests on thin-walled tubes. The method is based on analytical solutions for the quasi-steady state temperature distributions in a thin-walled ring heated by a rotating temperature source and a thin-walled tube heated by a helically moving source; using these solutions, remote temperature measurements on the tube can be used to back-calculate an effective source temperature which corresponds physically to an average deformation zone temperature. The method has been used in a broad range of experiments on steel, brass, aluminum, and cast iron to verify cutting temperature models. Sample calculations and infrared thermograms from these experiments are used to illustrate the application of the method.