Study on the structure of nanolayered TiAlN/TiN multilayer PVD hard coatings

Abstract: The aim of the project is to investigate how the conditions of the PVD influence the microstructure and behaviour of multi-layered TiAlN/TiN coatings. The multilayered samples evaporated at low (1 rpm) and fast (5 rpm) rotation rates were analysed using XRD, DSC and SEM techniques in the previous work. The most important DSC result was obtained for the multi-layered TiAlN/TiN 5 rpm coating where the transformation of the metastable fcc-AlN into the stable hcp-AlN structure was slowed down. XRD analysis for the multi-layered TiAlN/TiN samples had shown that there was the epitaxial growth for the thin layers obtained during the fast rotation at the same time, the analysis of TiAlN/ZrN coatings that were carried out for reference had show that there was no epitaxial growing. The aim of this work is to analyse the samples using TEM, DSC and nanoidentation to complete the information about the structure and properties of the coatings on the different stages of transformation. And to get the faithful representation of what happens when heating the film during the temperature where the hcp-AlN phase formation is expected. It could be interesting to check if the profiles analyses by using EELS and EDX techniques could help to clarify the structure formation process.