Effect of Yttrium Doping on the Structure and Tribological Properties of Mosx Coatings in Humid Atmosphere

Abstract

To enhance the friction performance of the MoSx coating in humid air, MoSx-Y composite coatings with varying yttrium contents were fabricated by direct current magnetron sputtering. The impact of the Y doping and the corresponding doping content on the structural characteristics, mechanical properties, and tribological performances of the MoSx coating was investigated. The results indicate that the doped Y element mainly existed in the form of Y2O3 within the coating. As the Y element content increased, the hardness and elastic modulus of the MoSx-Y composite coating gradually increased. The tribological properties of the coatings with different Y contents under a humid atmosphere (RH=60%) were comprehensively evaluated through rotary friction experiments. The experimental results reveal that the introduction of appropriate Y contents can effectively reduce the friction coefficient of the MoSx coating in a humid environment to approximately 0.1,and significantly enhance its friction life. The doping of the Y element inhibits the growth of the (100) and (110) planes of MoSx, causing the coating to grow preferentially along the (002) plane, which is an important factor contributing to the enhancement of the tribological properties of the MoSx coating by yttrium doping. This work demonstrates the controllability and potential of the tribological properties of the MoSx coating.

Keywords: Molybdenum disulfide, Composite coating, Yttrium doping, Tribology