45#钢表面复合润滑结构的制备及其摩擦性能研究

采用激光微加工技术在45#钢表面制备了微坑型织构,将激光表面织构化与MoS2固体润滑剂相结合在45#钢表面制备了复合润滑结构.研究了其在干摩擦条件下的摩擦磨损性能,考察了织构面密度及织构化微坑大小对其摩擦性能的影响.通过扫描电镜与能量色散谱仪对磨斑表面进行了分析.结果表明:与未织构面相比,织构面具有低而稳定的摩擦系数和高的耐磨寿命;对同一孔径织构面,随着织构密度的增加其表面摩擦系数随之减小,较适宜的织构密度为20%～35%;对同一织构面密度,当织构面密度小于20%时,较小孔径织构面的摩擦系数更低;织构面密度增至35%后,织构面摩擦系数则随孔径增大而减小;由于织构面复合润滑结构中的微坑有效地储存了润滑剂从而在摩擦过程中维持表面润滑薄膜的形成.

Preparation of Composite Lubrication Structure and its Tribological Properties on 45# Steel Surface

The composite lubrication structures were prepared by incorporation of solid lubricant into micro-dimples produced by laser surface texturing on the surface of 45# steel.The tribological properties of solid lubricant films on textured surfaces were compared with the behavior of burnished solid lubricant films on ground surfaces.The effects of the density and the diameter of the dimple reservoirs on the tribological properties were investigated.The wear tracks of the samples were observed using scanning electronic microscopy(SEM) and energy dispersive spectrometer(EDS).The results show that a significant decrease in friction and wear was achieved for the textured surfaces compared to that of untextured surfaces.It is shown that the friction coefficient reduced with increasing dimple density for the same dimple diameter.Optimum density(20%~35%) of the dimples was revealed.When the dimples density was less than 20%,the friction coefficient was lower for the textured surface with small dimple diameter.However,the friction coefficients increased with reducing of dimple diameter when the dimples density is more than 35%.The analysis of samples surfaces showed that low friction and long wear lifetime of burnished film on LST steel surfaces was apparently provided by preservation of thin MoS2 film around the dimples and by supply of solid lubricant from the dimples to the surface.