THE EFFECT OF Ni ON STRUCTURE AND PROPERTIES OF ADAPTIVE WEAR-RESISTANT ARC-PVD Ti-Al-Mo-N COATINGS

摘要

Coating samples of Ti-Al-Mo-N and Ti-Al-Mo-Ni-N composition were obtained by arc-PVD method. Ni addition to the Ti-Al-Mo-N system caused reducing the average grain size from 35 to 12 nm due to restriction of the nitride phase grains growth. The stresses of the coating material decreased from -2.25 GPa to -0.58 GPa. At the same time, the hardness of the coatings measured by microindentation was 37 GPa for Ti-Al-Mo-N and 45 GPa for Ti-Al-Mo-Ni-N. Ni-containing coatings demonstrated higher heat resistance, protecting the substrate from oxidation at the temperatures up to 700°C due to formation of the Ni-containing oxide phases. However, tribological tests of this coating at 500°C showed the insignificant increase in wear in comparison with Ti-Al-Mo-N coating and changing wear mechanism to abrasive.