Influence of Mo content on properties of Ti–Al–Mo–N films

Abstract

Ti-Al-Mo-N composite films with different molybdenum content were deposited by reactive magnetron sputtering. The results showed that the films consisted of fcc-(Ti, Al, Mo) N substitutional solid solution within 8.2 at.-% Mo. The films consisted of two phases which were fcc-(Ti, Al, Mo) N substitutional solid solution and fcc-Mo 2 N at 27.7-49.4 at.-% Mo. The hardness increased slowly at 0-27.7 at.-% Mo and then increased rapidly at above 27.7 at.-% Mo. A ball-on-disc dry sliding test was conducted on films deposited on stainless-steel substrates. The friction coefficient quickly decreased within 8.2 at.-% Mo and then gently declined at 8.2-49.4 at.-% Mo. The value of wear rate remained quite constant for compositions in the range 0-34.3 at.-% Mo and then dropped quickly at 34.3-49.4 at.-% Mo. The addition of Mo content effectively improved the hardness and tribological properties of the films.