复合润滑结构改善滑动导轨表面爬行现象研究

Reseach on Improvement of Creeping Phenomenon of Sliding Guideways by Composite Lubrication Texture

滑动导轨在低速重载时产生爬行现象,严重影响机床的加工精度。为了改善滑动导轨的爬行现象,对滑动导轨表面复合润滑结构的设计和摩擦力分阶段表征进行了研究。在激光烧蚀微织构的基础上,采用高温高压镶嵌法制备了复合润滑微织构,基于摩擦试验,提出了摩擦力分阶段表征方法,探索了不同复合润滑结构对各阶段摩擦力特征参数的影响规律,建立了复合润滑结构改善爬行现象的理论模型,找到抑制爬行现象性能最优的复合润滑结构。研究结果表明:表面微织构仅影响摩擦力的严重黏滑和爬升阶段,而复合润滑结构对整个启动阶段都有显著影响。填充二硫化钼(MoS 2)的正弦沟槽与六边形凹坑组合的多级复合润滑结构(SF-3)改善表面接触状态和抑制爬行现象的效果最好。与光滑表面(SS)试样相比,SF-3试样爬行时间缩短了72%,第Ⅰ阶段失稳力减小了69.83%,第Ⅱ阶段和第Ⅲ阶段的摩擦突跃力分别减小了75.91%和80.17%。

The creeping phenomenon of sliding guideways at low speed and heavy load seriously affected the machining accuracy of the machine tools.In order to improve the creeping phenomenon of the sliding guideways,the design of composite lubrication structure on the surfaces of sliding guideways and the characterization of friction force in stages were studied.The composite lubricating micro-texture was prepared by high temperature and high-pressure mosaic method based on the laser ablation micro-texture.The characterization methods of friction force in stages were proposed by friction tests.The influences of different composite lubricating structures on the friction characteristic parameters of each stage were explored.The theoretical models of the composite lubricating structures to improve the creeping phenomenon were established,and the composite lubricating structures with the best performance to suppress the creeping phenomenon were found.The results show that the surface micro-texture only affects the severe stick-slip and climb stages of friction force,while the composite lubrication texture has a significant effect on the entire start-up stage.The multi-stage composite lubrication texture(SF-3)with the combination of sinusoidal grooves and hexagonal pits filled with molybdenum disulfide(MoS 2)was the most effective in improving the surface contact conditions and suppressing the creep phenomenon.Compared to the smooth surface(SS)sample,the creep time of the SF-3 sample is reduced by 72%,the instability force in the first stage is reduced by 69.83%,and the friction jump force in the second and third stages is reduced by 75.91%and 80.17%,respectively.