Restspänningar i arc-förångade (Ti(1-x)Al(x))N ytskikt
This report is the written documentation of a project work carried out at the Division of Engineering Materials at Luleå University of Technology in cooperation with Seco Tools AB. The project deals with the analysis of residual stresses in Ti-Al-N thin film grown on WC/Co cutting inserts. The composition of Al varied from 0% up to 75%. Increasing the Al content in the Ti(1-x)Alx N compound improves the compressive residual stresses even after annealing of the material. The experiments have been performed in a high temperature x-ray diffractometer (HTXRD) where the interplanar atomic spacing was determined in-situ and subsequent converted into stresses. In addition, tests have been performed to determined the coefficient of thermal expansion for the different compounds. This analysis was made from powders to avoid the interference of stresses. These coefficients have been used to determine the thermal contriribution to the residual stress and are compared to the stresses experimentally determined. The goal was to increase the understanding for the behaviour of the material in an environment close to the temperature experienced during the cutting operation and further the understanding of these new materials.