不同电流下超音速等离子喷涂钼-钨复合涂层的性能

摘要

MoW composite coatings were prepared on the surface of 45CrNiMoVA steel by supersonic plasma spraying at a Mo-to-W mass ratio of 4∶1.The micro-morphology,elemental composition,phase structure,microhardness and wear resistance of the coatings prepared at different spraying currents were studied by scanning electron microscope,energy-dispersive spectrometer,X-ray diffractometer,microhardness tester and tribometer.The results showed that spraying current has a significant effect on the MoW composite coating.The coating prepared at a spraying current of 350 A has the best performance.Either too large or too small spraying current will lead to a loose coating with enlarged pores.MoW composite coating significantly improves the microhardness and wear resistance of the substrate.It was found that a thin layer of wear-resistant oxide film is formed both on the surfaces of coating and substrate during the frictional wearing process.%将Mo粉和W粉按质量比4∶1混合后用超音速等离子喷涂系统在45CrNiMoVA钢表面制备了Mo-W复合涂层.通过扫描电镜、能谱仪、X射线衍射仪、显微硬度计和摩擦磨损试验机考察了不同喷涂电流下所制涂层的微观形貌、成分、物相、显微硬度及耐磨性.结果表明,喷涂电流对Mo-W复合涂层影响显著,喷涂电流为350 A时所制涂层的各项性能最好.电流过大或过小均会导致涂层疏松,孔隙增大.Mo-W复合涂层显著提高了基体的显微硬度及耐磨性.在摩擦磨损过程中涂层和基体表面均生成了一层薄薄的耐磨氧化膜.