激光熔覆/离子渗硫复合改性层的表征与减摩行为

采用激光熔覆和离子渗硫复合处理在Ni基金属陶瓷涂层表面原位合成微纳米硫化物固体润滑薄膜,得到复合改性层。采用XRD、XPS、SEM、AFM、EPMA等方法对复合改性层进行了表征,在摩擦磨损实验机上研究了复合改性层干摩擦条件的摩擦磨损性能。结果表明,Ni基金属陶瓷涂层主要由γ-(Fe,Ni)、Cr2Ni3、Ni17W3、Fe0.64Ni0.36、WC、Cr7C3和CrSi2组成,显微硬度在550~625 HV0.2。渗硫层是一个3~4μm的灰黑色带状层,与基体之间无明显过渡,表面疏松而多孔,由微纳米级的尖岛状颗粒堆砌而成;渗硫层主要由单质Fe、Ni,FeS、FeS2、NiS等硫化物,Fe、Cr的氧化物组成。摩擦磨损实验结果表明,与Ni基金属陶瓷涂层相比,复合改性层的摩擦系数和磨损量都显著降低。

Characterization and Anti-friction Behaviors of Composite Coating Produced by Laser Cladding and Ion Sulfurization

Micro-nano sulfide solid lubrication film was in-site synthesized on the surface of Ni-based cermets coating by laser cladding and ion sulfurization and then composite coating was produced.XRD,XPS,SEM,AFM and EPMA were used to characterize the composite coating.The friction and wear properties without oil lubrication were tested on friction and wear tester.The results show that cermets coating is mainly composed of Cr2Ni3,γ-(Fe,Ni),Ni17W3,Fe0.64Ni0.36,WC,Cr7C3 and CrSi2.The microhardness is 550~625 HV0.2.Sulfide layer is a grey and black belt course,without obvious transition zone with cermets coating.The thickness of sulfide layer is about 3~4μm.The surface of sulfide layer is loose and porous,constructed of micro-nano lever sharp-island particles.The sulfide layer is mainly composed of simple substance Fe,Ni,FeS,FeS2,NiS,chromium oxide and iron oxide.The result of friction and wear test indicates that the friction coefficient and wear loss of composite coating decrease apparently,compared with Ni-based cermets coating.