| AVS 60th International Symposium and Exhibition | |
| Advanced Surface Engineering | Thursday Sessions |
| Session SE+NS+TF-ThA |
| Session: | Nanostructured Thin Films and Coatings |
| Presenter: | N. Norrby, Linköping University, Sweden |
| Authors: | N. Norrby, Linköping University, Sweden H. Lind, Linköping University, Sweden G. Parakhonskiy, University of Bayreuth, Germany M.P. Johansson-Jõesaar, Linköping University, Sweden F. Tasnádi, Linköping University, Sweden L.S. Dubrovinsky, University of Bayreuth, Germany N. Dubrovinskaia, University of Bayreuth, Germany I.A. Abrikosov, Linköping University, Sweden M. Odén, Linköping University, Sweden |
| Correspondent: | Click to Email |
As-deposited cubic Ti0.60Al0.40N, mainly used as a hard coating on metal cutting tools, decomposes in two steps at elevated temperatures and ambient pressure. The first step is a spinodal decomposition where coherent nanostructured cubic TiN- and AlN-rich domains are formed, after which a transformation of cubic AlN into hexagonal AlN is followed. In the present work, the decomposition of arc evaporated Ti0.60Al0.40N at elevated temperatures and quasi hydrostatic pressures has been studied both experimentally and by first-principles calculations. High pressure and high temperature treatment of the samples was realized using the multi anvil press and diamond anvil cell techniques. The products of the HPHT treatment of Ti0.60Al0.40N were investigated using x-ray diffractometry and transmission electron microscopy. Complimentary calculations show that both hydrostatic pressure and high temperature stabilize the cubic phase of AlN which is in excellent agreement with the experimental results. In addition, the experimental results suggest that the presence of Ti in the system serves to increase the stability region of the cubic AlN phase. The results are industrially important as they show that Ti0.60Al0.40N coatings on cutting inserts do not deteriorate faster under pressure due to the cubic AlN to hexagonal AlN transformation.