Performance of MoS2/metal composite coatings used for dry machining and other industrial applications

Abstract

As previously reported (Fox et al., Proc. PSE Conf., Garmisch Partenkirchen, 14–18 September, 1998), the properties of MoS2 coatings can be improved by the co-deposition of a small amount of titanium. These MoS2/Ti coatings, known as MoST™ produced by closed field unbalanced magnetron sputtering, are harder, much more wear resistant and less sensitive to atmospheric water vapour. These coatings have given excellent industrial results for a wide range of cutting and forming applications. Two forms of these MoS2/titanium composite coatings have been developed: MoS2/titanium composite (low titanium, 10 at%) and MoS2/titanium composite (high titanium, 20 at%).

The MoS2/titanium composite (low titanium) exhibits a coating hardness of 500 HV, a coefficient of friction of 0.02 during 100 N applied load reciprocating wear testing, and a low wear rate, while the MoS2/titanium composite (high titanium) exhibits a coating hardness similar to that of TiN, a coefficient of friction of 0.04 during 100 N applied load reciprocating wear testing, and an extremely low wear rate.

The choice of coatings is dependent upon the application. Recent industrial performance data related to the characteristics of these MoS2/titanium composite (high titanium) self-lubricant coatings, which are utilised now in large-scale production, are presented.