载流下MoS_(2)/Ag纳米复合薄膜摩擦学性能

Friction and Wear Mechanism of MoS_(2)/Ag Nanocomposite Film under Current Carrying

MoS_(2)基纳米复合薄膜具有良好的摩擦学性能,但较差的导电性能限制了其在载流条件下作为润滑材料的应用。为提高MoS_(2)基纳米复合薄膜的导电性能,采用非平衡磁控溅射系统沉积2种不同Ag含量的MoS_(2)/Ag纳米复合薄膜,并在不同的电流条件下研究MoS_(2)/Ag纳米复合薄膜与GCr15钢球对摩时的摩擦学性能。结果表明:在载流下2种MoS_(2)/Ag纳米复合薄膜表现出相似的摩擦性能,而低掺杂MoS_(2)/Ag薄膜具有更佳的耐磨性能,这归因于低掺杂MoS_(2)/Ag薄膜具有较好的力学性能;无载流时,MoS_(2)/Ag纳米复合薄膜在摩擦过程中生成的氧化物颗粒增加了磨损、降低了润滑性,磨损机制主要为磨粒磨损;电流小于0.5 A时,电流促进了转移膜形成,使得摩擦因数降低,但磨损率增加,磨损机制主要为黏着磨损;当电流大于0.5 A时,由于电弧烧蚀加速了薄膜的磨损,磨损机制主要为磨粒磨损、黏着磨损和电弧腐蚀磨损。

MoS_(2)-based nanocomposite films have good tribological properties,but the poor electrical conductivity limits their application as lubricating materials under current carrying conditions.In order to improve the electrical conductivity of MoS_(2)-based nanocomposite film,the MoS_(2)/Ag nanocomposite films with two different Ag contents were fabricated using an unbalanced magnetron sputtering system,and their tribological properties against GCr15 steel ball under different current conditions were studied.The results show that the two kinds of MoS_(2)/Ag films have a similar friction performance under current carrying,while the low-doped MoS_(2)/Ag nanocomposite film exhibits superior wear resistance.This is due to the better mechanical properties of the low-doped MoS_(2)/Ag nanocomposite film.When there is no current carrying,the oxide particles generated in the friction process of MoS_(2)/Ag nanocomposite films increase wear and reduce lubrication,and the wear mechanism is mainly abrasive wear.When the current is less than 0.5 A,the current promotes the formation of the transfer film,which reduces the friction coefficient,but increases the wear rate,and the wear mechanism is mainly adhesive wear.When the current is higher than 0.5 A,the wear of the film is accelerated by arc ablation,and the wear mechanisms are mainly abrasive wear,adhesive wear and arc corrosion wear.