真空退火对磁控溅射CuS-MoS2涂层润滑性能的影响

为提高MoS2润滑涂层承载力和抗湿性能,使用磁控溅射技术制备CuS掺杂MoS2复合涂层,并对制备涂层进行220、320和420℃真空退火处理,以发挥CuS与MoS2协同润滑作用。采用场发射扫描电子显微镜、激光拉曼光谱分析涂层结构,通过洛氏硬度压痕试验、摩擦磨损试验和纳米压痕试验对涂层性能进行分析。实验结果表明:随CuS靶溅射功率提高,涂层中出现颗粒长大和CuS结晶化趋势,且CuS掺杂抑制了MoS 2形核长大,涂层膜-基结合力有所下降;真空退火处理后CuS-MoS2复合涂层表面发生分解,厚度明显降低,MoS2(002)相形核长大,摩擦学性能得到提升;320℃退火处理后涂层在常温和RH70%大气环境下获得最低平均摩擦因数0.08,纳米硬度达到5.64 GPa,并具有较好的耐磨损性能。研究认为由于CuS受热分解导致复合涂层结构和成分变化,生成了有利于发挥CuS与MoS2协同润滑效应的微晶相,使得涂层润滑性能得到明显提升。

Effects of Vacuum Annealling on Lubrication Properties of CuS-Doped MoS2 Coatings Grown by Magnetron Sputtering

To improve the load-bearing capacity and humidity resistance of MoS2 lubricating coating,CuS-doped MoS2 composite coatings were prepared using magnetron sputtering,and the as-grown coatings were annealed in vacuum at 220,320 and 420℃,to release synergistic effects of CuS in MoS2 lubricant.The microstructure of the coating was observed by field emission scanning electron microscopy,the molecular structure of the coating was analyzed by laser Raman spectroscopy,the adhesion of the coating was qualitatively analyzed by Rockwell hardness test,and the lubrication properties of the coating were evaluated by friction and wear tester.The results show that with the increase of sputtering power of CuS target,the particles in the coating grow and the crystallization of CuS appears in the coating,and the bond strength of film-substrate is also decreased.After vacuum annealing,the surface of CuS-MoS2 coatings is decomposed,the thickness is decreased.The nucleation of MoS2(002)grows and tribological properties are improved.After annealing at 320℃,the coating gets the lowest average friction coefficient of only 0.08 at room temperature and RH70%,nano-hardness is 5.64 GPa and has good wear resistance.This reveals that the changes of structure and composition of CuS-MoS2 coatings are beneficial to the synergistic lubrication effect of CuS and MoS2,which are due to the decomposition of CuS and the formation of microcrystalline phase.