H13激光微织构下的类石墨烯固体润滑机理研究

发布时间：2018-01-09 15:12

本文关键词：H13激光微织构下的类石墨烯固体润滑机理研究　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：相互接触的两物体在发生相对运动过程中必然存在摩擦,摩擦、磨损与润滑是正确认识摩擦学的三个关键点,合理减小摩擦磨损,改善摩擦副的润滑状态是延长机器服役寿命、提高工作效率、减小不必要经济损失的有效举措。表面织构作为一种仿生学技术已受到广大学者重视,而固体润滑相比液体润滑展现出了更好的润滑效果,表面织构固体润滑技术也就应运而生。本文结合有限元模拟、工艺技术和摩擦试验系统开展了H13表面织构固体润滑的摩擦性能及机理研究。主要研究结论如下:首先,在建立环—环接触的二维截面模型的基础上,采用控制变量法从应力的角度分析了织构固体润滑机理及织构参数(直径、深度和密度)对应力的影响,结果表明,织构的存在改变了接触面间的应力分布情况,缓解了接触面间的应力集中现象。然后设计了正交试验对织构参数进行了优化。结果表明,织构参数对应力的影响从小到大依次为直径密度深度,且最优的织构参数组合为直径140μm、密度23%、深度14μm。其次,使用K20-CS型光纤激光打标机对H13试样进行表面织构加工工艺研究。结果表明,表面织构的几何参数(直径D和深度h)均随着打标机输出功率的增大而增大;随着打标次数的增加,织构深度几乎呈线性增长,但直径却呈现出先增大后减小的变化趋势;随着激光扫描速度的增加,微织构直径呈增大的变化趋势,而深度的变化却是随着激光扫描速度的增加而减小,且500mm/s扫描速度是微织构直径和深度显著变化的转折点;激光微织构在靠近微凹坑处的硬度有所增加,尤其是微织构中的硬度较基体硬度提升了56.82%。利用“冷压粘接法”对固体润滑剂的填充工艺进行了探讨与表征,结果表明,在模具加压的情况下,固体润滑剂有较好的填充效果,该方法计算出的单个织构的填充率约为96.35%,整体表面微织构的填充率约为83.33%。最后,利用MWW-1A型微机控制万能摩擦磨损试验机进行摩擦试验。结果表明,在当前实验条件下,其平均摩擦系数随复合固体润滑剂中MoS_2的质量比的增加而呈现出先减小后增加的变化趋势,且当质量比为40%时,复合固体润滑剂的润滑效果最佳;四种不同织构排布的平均摩擦系数从小到大依次为:环形排布,弧形排布,线性排布和方形排布;与其他试样相比,织构固体润滑试样的润滑状态最佳,摩擦系数和磨损均最小,且摩擦系数变化幅度受转速和载荷变化影响较小。
[Abstract]:Friction, friction, wear and lubrication are the three key points of tribology to reduce friction and wear reasonably. To improve the lubricating state of friction pairs is an effective measure to prolong the service life of the machine, improve the working efficiency and reduce the unnecessary economic loss. Surface texture as a bionic technology has been paid attention to by many scholars. Compared with liquid lubrication, solid lubrication shows better lubrication effect, and surface texture solid lubrication technology emerges as the times require. This paper combines finite element simulation. The friction properties and mechanism of solid lubrication of H13 surface texture have been studied by technology and friction test system. The main conclusions are as follows: firstly, a two-dimensional section model of ring-ring contact is established. The mechanism of texture solid lubrication and the influence of texture parameters (diameter, depth and density) on the stress are analyzed from the stress point of view by the method of controlling variables. The results show that the influence of texture parameters (diameter, depth and density) on the stress is discussed. The existence of texture changes the stress distribution between the contact surfaces and alleviates the stress concentration between the contact surfaces. Then the orthogonal test is designed to optimize the texture parameters. The effect of texture parameters on stress is from small to large, and the optimum texture parameters are 140 渭 m in diameter, 23 in density and 14 渭 m in depth. The surface texture processing technology of H13 sample was studied by using K20-CS fiber laser marking machine. The geometric parameters (diameter D and depth h) of surface texture increase with the increase of the output power of marking machine. With the increase of marking times, the texture depth increases linearly, but the diameter increases first and then decreases. With the increase of laser scanning speed, the diameter of microtexture increases, while the depth decreases with the increase of laser scanning speed. The scanning velocity of 500mm / s was the turning point of the significant change in the diameter and depth of microtexture. The hardness of laser microtexture near the microcrater is increased. In particular, the hardness of microtexture is 56.82 higher than that of matrix. The filling process of solid lubricant is studied and characterized by "cold pressing bonding method". The results show that under the pressure of die, the filling process of solid lubricant is investigated and characterized. Solid lubricant has good filling effect. The filling ratio of single texture is about 96.35 and the filling rate of whole surface microtexture is about 83.33. finally. The friction test is carried out by using MWW-1A microcomputer controlled universal friction and wear tester. The results show that under the current experimental conditions. The average friction coefficient decreases first and then increases with the increase of mass ratio of MoS_2 in composite solid lubricant, and when the mass ratio is 40, the lubricating effect of composite solid lubricant is the best. The average friction coefficient of four different texture arrangement is as follows: ring arrangement, arc arrangement, linear arrangement and square arrangement; Compared with other samples, the texture solid lubrication samples have the best lubrication condition, the friction coefficient and wear are the smallest, and the variation of friction coefficient is less affected by the change of rotational speed and load.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG178;TH117.2

【参考文献】