Impact of annealing on microstructure, properties and cutting performance of an AlTiN coating

In this study, cemented carbide inserts with nano-crystalline Al0.67Ti0.33N coating deposited by cathodic arc evaporation, were annealed in vacuum at temperatures 700 and 900 °C during a time period of 2  h and ran through a turning test. The micro-structural characteristics, a number of micro-mechanical properties (microhardness, elastic modulus, elastic recovery parameter, microhardness dissipation parameter, critical load values during scratch testing, low cycling wear resistance) measured at room and elevated temperatures (up to 600 °C) as well as cutting tool life and wear behavior have been investigated before and after annealing using optical metallography, SEM, XRD, XPS, and HREELS methods. The results indicate the impact of microstructure formed during annealing on the mechanical and tribological properties as well as wear behavior of cutting tools with a Al0.67Ti0.33N coating.