In-situ high-temperature synchrotron XRD on CVD AlTiN coatings: an industrial case study

Purpose and goal:

The aim of the project was partly to explore the possibility of using in-situ high-temperature high-energy grazing incidence transmission synchrotron X-ray diffraction (HT-HE-GIT-XRD) to investigate samples and research questions that are of interest for the cutting tool industry, and partly to transfer knowledge from academia to industry for how to setup, perform HT-HE-GIT-XRD experiments at a synchrotron facility and evaluate the collected data from this kind of experiment. Both these goals have been successfully achieved.

Expected results and effects:

Using HT-HE-GIT-XRD it was possible to follow in-situ the phase transformation and stress evolution happening in thin (Al,Ti)N coatings that were rapidly heated up to 1200 °C. How different post-treatment protocols for the coatings affected phase transformation and stress evolution could be investigated and compared with each other. Doing similar in-situ investigations are not feasible in a normal lab.

Thus, the results show that HT-HE-GIT-XRD can serve as a useful tool for industry, giving data and answers to research questions not obtainable with other techniques. Approach and implementation:

The project partners applied for and obtained beam time at P07, PETRA III, Hamburg. During the beam time, sixteen samples were investigated. All samples were eight micron thick chemical vapor deposited (Al,Ti)N coatings deposited on cemented carbide inserts that had undergone different post-treatment protocols.

During the experiment, the samples were exposed to rapid heating in an inert atmosphere. After the beam time, scripts for how to analyze the data were created at Chalmers and later shared with the industrial partners, Sandvik Coromant and Walter AG.