Effect of Al target sputtering power on themicrostructure and tribological properties of CrAlN coatings

In order to explore the direct effects of Al target power on theproperties of CrAlN coatings, the coatings were deposited on 304 stainless steel substrate by DC reactive magnetron sputtering method. The experiment studied the effects of different AI target power on the microstructure and friction properties of the coatings. The phase composition, surface morphology, friction and wear property, wear track morphology and hardness of the samples were characterized by SEM, XRD, AFM, reciprocating friction and wear testing machine, microhardness tester and 3 D surface profiler. The results show that the grain size of the coatings has a slight tendency of increasing and then decreasing with the increase of Al target power. It is at minimum when the target power is 180w. With the increase of Al target power, the microhardness and average deposition rate have a tendency of increasing first and then decreasing. However, wear depth and average volume wear rateare just the opposite. After comparison, the comprehensive performance of CrAlN coatings is the best when the Al target power is 150 W.