Improvement of the tribological properties of Al2O3 reinforced duplex stainless steel MMC coating by the addition of TiS2 powder

The friction coefficient and the wear rate of the coating against an Al2O3 pin were lower compared to the corresponding values of the coating prepared without the addition of TiS2. The Al2O3 reinforcement particles are surrounded by sulfides and thus they have better wettability by the molten stainless steel. As a result, they are less detachable compared to the Al2O3 particles of the coating fabricated without the addition of TiS2. In addition, since there is a metallurgical bond between the Al2O3 and the surrounding sulfide, it may be presumed that even when Al2O3 particles eventually detach, they are always surrounded by sulfides which not only prevent the oxides' action as a third body abrasive but also act as lubricants.