中国科学院材料磨损与防护重点实验室/先进润滑与防护材料研究发展中心知识库

Four types of NiCr-Cr₂O₃ composite coatings doped with different mass fraction of Nd₂O₃ were deposited by atmospheric plasma spraying. The microstructure and phase composition of as-sprayed coatings were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). Furthermore, their friction and wear behaviors at 20 and 600 ℃ under unlubricated condition were evaluated using CSM high temperature tribometer. The results showed that Nd₂O₃ could refine microstructure of NiCr-Cr₂O₃ composite coating and make Cr₂O₃ distribution more uniform in the coating, which leads to the increase of average microhardness. In addition, NiCr-Cr₂O₃ composite coatings doped with Nd₂O₃ had better wear resistance than that without Nd₂O₃ at experimental temperatures. Especially, the coating containing 8 wt.% Nd₂O₃ showed the best wear resistance at 20 and 600 ℃, which was attributed to the refined microstructure and improved microhardness. At 20 ℃, the wear mechanism of the coating was abrasive wear, brittle fracture and splat detachment. At 600 ℃, the wear mechanism was adhesion wear and plastic deformation.