Increase of hardness and thermal stability of TiAlN coating by nanoscale multi-layered structurization with a BN phase

This study investigated the effects of a nanoscale multi-layered structure on the hardness and thermal stability of Ti–Al–B–N coating. Bilayer period of nanoscale multi-layered TiAlN/BN coating, prepared by alternating deposition of TiAlN and BN layers, was controlled by changing BN target power. The hardness value of TiAlN coating increased through nanoscale multi-layered structurization with a thin (∼ 0.6 nm) BN phase. The intensity of low angle XRD peaks and hardness of the nanoscale multi-layered TiAlN/BN coatings increased after heat-treatment in an N2 atmosphere. The nanoscale multi-layered TiAlN/BN coating showed better thermal stability than that of TiAlN coating.