边界润滑条件下碳烟对摩擦反应膜机械性能的影响及其磨损机理研究

发布时间：2018-01-18 06:18

本文关键词：边界润滑条件下碳烟对摩擦反应膜机械性能的影响及其磨损机理研究　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：因燃油不完全燃烧而产生的碳烟会加剧发动机中活塞环/缸套摩擦副的磨损,降低发动机的使用寿命。尤其当活塞处于上、下止点时,这对摩擦副处于混合或边界润滑状态,碳烟所造成的磨损就更为严重。要解决这一问题,就必须探明碳烟对摩擦反应膜的影响,因为摩擦反应膜在很大程度上决定了处于混合或边界润滑状态下的摩擦副的摩擦学性能。本学位论文在不同实验条件下对含ZDDP(二烷基二硫代磷酸锌)和不同含量碳烟的液体石蜡进行了摩擦学实验,借助现代表面分析设备分别对摩擦表面的形貌、ZDDP摩擦反应膜的分布状态以及摩擦表面的力学性能进行了表征与分析,为研究碳烟的磨损机理提供了新的方法。研究了摩擦反应膜的机械性能随碳烟含量的变化。结果表明:随着碳烟含量的增加,摩擦表面ZDDP摩擦反应膜的厚度减小,在摩擦表面的覆盖率以指数形式降低;摩擦表面的硬度H降低,弹性模量E升高,平均H/E值以指数形式降低,且平均H/E值与ZDDP摩擦反应膜覆盖率呈线性关系。分别研究了未添加和添加3%碳烟时摩擦反应膜的机械性能随摩擦时间的变化。结果表明:随着摩擦时间的增加,不添加碳烟时的ZDDP摩擦反应膜厚度增加,摩擦表面的硬度H增大,弹性模量E稳定在170 GPa左右,平均H/E值增加;添加3%碳烟时的ZDDP摩擦反应膜厚度均匀性降低,摩擦表面的硬度H和弹性模量E出现波动,平均H/E值变化较乱;相对摩擦反应膜覆盖率和相对H/E值同步降低。分别研究了未添加和添加3%碳烟时摩擦反应膜的机械性能随载荷的变化。结果表明:随着载荷的增加,未添加碳烟时的ZDDP摩擦反应膜厚度先增大再减小,摩擦表面的硬度H先增加再降低,弹性模量E稳定,平均H/E值先增加再降低;添加3%碳烟时的ZDDP摩擦反应膜厚度降低,摩擦表面的硬度H先增加再降低,弹性模量E稳定,平均H/E值先增加再降低;相对摩擦反应膜覆盖率线以线性形式降低,相对H/E值先降低再升高。碳烟的磨损机理归于碳烟的磨粒磨损作用会将摩擦反应膜刮离摩擦表面,降低摩擦反应膜对基体的保护作用,进而使摩擦表面的力学性能降低,摩擦副的减摩抗磨性能由此减弱。
[Abstract]:The soot caused by incomplete combustion of fuel fuel will increase the wear of piston ring / cylinder liner friction pair in the engine and reduce the service life of the engine, especially when the piston is at the top and bottom check point. The wear caused by soot is more serious when the friction pair is in the condition of mixing or boundary lubrication. In order to solve this problem, the influence of soot on the friction reaction film must be investigated. The tribological properties of friction pairs in mixed or boundary lubricated state are largely determined by friction reaction film. In this dissertation, ZDDP (zinc dialkyl dithiophosphate) was prepared under different experimental conditions. Tribological experiments were carried out with liquid paraffin with different soot contents. The distribution state of ZDDP friction film and the mechanical properties of the friction surface were characterized and analyzed by means of modern surface analysis equipment. It provides a new method for studying the wear mechanism of soot and studies the change of mechanical properties of the friction reaction film with the soot content. The results show that: with the increase of soot content. The thickness of the ZDDP friction reaction film on the friction surface decreases and the coverage of the friction surface decreases exponentially. The hardness H of friction surface decreases, the elastic modulus E increases, and the average H / E value decreases exponentially. The average H / E value is linearly related to the coverage of the ZDDP friction reaction film. The mechanical properties of the friction reaction film with or without adding 3% soot are studied respectively. The results show that the mechanical properties of the film vary with the friction time. With the increase of friction time. Without soot, the thickness of ZDDP friction reaction film increases, the hardness H of friction surface increases, the elastic modulus E is about 170 GPa, and the average value of H / E increases. When 3% soot was added, the thickness uniformity of the ZDDP friction reaction film decreased, the hardness H and the elastic modulus E of the friction surface fluctuated, and the mean H / E value changed unsteadily. The relative friction film coverage and the relative H / E value decreased synchronously. The mechanical properties of the friction reaction film with and without adding 3% soot were studied respectively. The results showed that the mechanical properties of the friction reaction film varied with the increase of the load. Without soot, the thickness of ZDDP friction reaction film first increases and then decreases, the hardness H of friction surface increases and then decreases, the elastic modulus E is stable, and the average H / E value increases first and then decreases. When 3% soot was added, the thickness of ZDDP friction reaction film decreased, the hardness H of friction surface increased and then decreased, the elastic modulus E was stable, and the average H / E value increased first and then decreased. The coverage line of relative friction reaction film decreases linearly and then increases relative to H / E. the wear mechanism of soot is attributed to the abrasive wear effect of soot which will remove the friction reaction film from the friction surface. By reducing the protective effect of the friction reaction film on the substrate, the mechanical properties of the friction surface are reduced, and the friction and antiwear properties of the friction pair are weakened.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH117.1

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