Properties of (Ti,Cr)N and (Al,Cr)N thin films prepared by ion beam assisted deposition

(Ti,Cr)N and (Al,Cr)N thin films were prepared by nitrogen ion beam assisted deposition of Cr, Ti or Al (IBAD) atoms on a titanium, chromium or aluminium substrate. In this way, layers featuring a diverse composition were obtained. The actual profile of the implanted and deposit atoms differed from the theoretically assumed process. Some of the implanted nitrogen formed gas bubbles under the sample's surface. The gas bubbles released the nitrogen upwards while the local temperature increased during the implantation or during a later heating process. Craters are formed from the bubbles, which were clearly visible on the AFM photographs. Annealing the modified surfaces in a vacuum always changed the surface topography of the sample. The lowest wear rate and the lowest friction coefficient were observed in the Cr-Ti-N and Cr-Al-N samples.