Role of Mo particles on microstructure and tribological properties of atmospheric plasma sprayed Mo reinforced BN-NiCr coatings

Abstract Atmospheric plasma spraying was employed to prepare NB (BN-NiCr) and NM (Mo/BN-NiCr) composite coatings. The incorporation of Mo particles reduced the friction coefficient of NM coatings (0.35–0.42) compared to NB coating. However, excessive Mo content can cause particle rebound, negatively affecting friction performance. The self-lubricating properties of Mo and the layered structure of BN form a lubricating film at the friction interface, reducing the wear rate. Additionally, Mo particles enhance the NiCr coating’s strength and wear resistance. The wear mechanism transitions from adhesive to abrasive wear, with localized high temperatures during friction promoting the formation of oxide films, such as NiO, Cr 2 O 3 , and MoO 3 , further improving the wear resistance.