Molybdenum oxide coatings deposited on plasma nitrided surfaces

Molybdenum trioxide (MoO₃) thin films are generally deposit on metallic surfaces to increase their tribological performance. In this manuscript, MoO_x coatings were for the first time deposited on plasma nitrided surfaces. Vickers microhardness tests, X-ray diffractometry, and micro abrasive wear tests characterized the samples. It was investigated the effect of temperature in hardness and tribological properties of austenitic stainless steel surfaces. When the temperature of plasma nitriding increases, the coating thickness and the nitrogen diffusion on the treated surface also increases, favoring the hardness of the coatings. After MoO_x deposition, the predominant MoO₃ phase with monoclinic and orthorhombic unit cells was observed. MoO_x coatings after plasma nitriding demonstrated the highest wear resistance. (author)