【作者】 闫艳红；

【导师】 肖宏； 杨育林；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2009， 博士

【摘要】 摩擦学的发展已将摩擦磨损研究从减摩抗磨扩展到磨损表面自修复甚至零磨损,其中,在线自修复已成为当今摩擦学研究热点,这对节能降耗要求越来越迫切的今天,具有重要的理论与应用意义。近年来,对自修复添加剂的研究多集中于钢摩擦副上。有研究表明,在自修复添加剂润滑下,45钢磨损表面能够在线生成自修复保护膜,有效地减少了金属磨损、延长了材料使用寿命。铸铁作为重要的工程材料,广泛应用于机械制造业,在铸造合金中,铸铁的产量约为75%~80%。若自修复添加剂能明显改善铸铁的摩擦磨损性能,可进一步扩大其在工业上的应用,降低生产成本。因此,开展自修复添加剂对含铸铁配副的摩擦磨损性能的研究具有重要的实际意义。本文选取自修复添加剂对含铸铁配副摩擦磨损性能的影响作为研究课题。选用MMU-5G屏显式材料端面摩擦磨损试验机作为试验平台,自主设计便于润滑的试验试样,自备亚微米级羟基硅酸盐粉体作为磨损自修复添加剂,对含铸铁配副:45钢/铸铁、铸铁/45钢以及铸铁/铸铁摩擦副进行了大量的摩擦磨损试验。研究了自修复添加剂浓度、添加剂的时间效应、载荷效应以及摩擦副间相对滑动速度等因素对自修复添加剂润滑下的含铸铁配副摩擦磨损性能的影响,借助扫描电镜观察试样的磨损表面及断面形貌,借助能谱仪对试样表面和断面进行成分分析,揭示含铸铁配副在自修复添加剂作用下的摩擦磨损行为,初步探讨自修复添加剂对铸铁的作用机理。结果表明,不同工况参数对自修复添加剂作用下的含铸铁配副的摩擦磨损性能影响十分明显。当自修复添加剂浓度、磨损时间、摩擦副所加载荷以及摩擦副间相对滑动速度适宜时,铸铁及含铸铁配副在自修复添加剂润滑下表现出良好的摩擦磨损性能。在整个试验过程中,含铸铁配副的摩擦系数较0%添加剂时明显减小,铸铁试样的磨损量明显降低,自修复添加剂对铸铁的减摩抗磨效应显著;试验发现,45钢试样在与铸铁对磨时,其磨损表面仍能发生自修复反应,生成自修复保护膜,而铸铁因其金相组织和机械性能的特点,磨损表面无法发生自修复反应。本文的研究结果对于进一步开展对铸铁在自修复添加剂润滑下的摩擦磨损性能以及自修复膜生成状况的研究具有重要的参考价值,为自修复添加剂在含铸铁配副上的应用提供了一定的试验依据。更多还原

【Abstract】 The development of tribology has expand the antifriction and antiwear of the researches on friction and wear into the self-repairing of worn surface, even zero wear, among them, repairing the early worn surface on-line has become the hotpot of the tribology researches.Today, in the increasing urgent demands of energy-saving and consumption-decreasing, it is of important academic and practical significance.For the past few years, the researches on self-repairing additive chiefly focused on frictional pairs of steel. Previous studies have shown that self-repairing coating can be generated on the worn surface of 45steel on-line, which reduces wear of metal materials and increases the service life.Cast iron is widely used in machine building industry as a important engineering material, in casting alloy, the output of cast iron is about 75 to 80 percent.If cast iron shows good friction and wear characteristic under self-rpairing additive, its application in industry will be further increased, and greatly reduce manufacturing cost. So, carrying out a research on friction and wear characteristics of pairs containing cast iron in self-repairing additive is of important practical significance.The research of influence of self-repairing additive on friction and wear characteristics of friction pairs with cast iron was chosen as a subject in this paper. MMU-5G end-face friction and wear testing machine was used as testing platform, experimental samples were designed independently which were convenient for being lubricated, hydroxy silicate powder were prepared by ourselves as self-repairing additive.On this condition, large numbers of experiment on friction and wear characteristics of friction pairs containing cast iron such as 45steel/cast iron,cast iron/45steel and cast iron/cast iron pairs were carried out, the influence on the friction and wear characteristics of friction pairs containing cast iron of concentration of self-repairing additive, wear time, the load on the friction pairs and the relative sliding speed of the pairs were studied systemically.The feature of worn surfaces and sections were observed by means of scanning electron microscopy, component of worn surfaces and sections were analyzed by means of energy disperse spectroscopy, the behavior of friction and wear of pairs containing cast iron in self-repairing additive have been known, and the mechanism of self-repairing additive are discussed.The results indicates that various working conditions parameters have a remarkable influence on friction and wear characteristics of friction pairs containing cast iron.When concentration of self-repairing additives, wear time, the load on the friction pairs and the relative sliding speed of the pairs are suitable,cast iron and the pairs containing cast iron have shown good performance of friction and wear.In the whole process,the frictional coefficient of pairs containing cast iron had decreased obviously comparing with ones in no additive,the weight losses of cast iron had reduced obviously from beginning to end, self-repairing additive has remarkable effect on antifriction and wearing of cast iron.The experimental results shows, self-repairing reaction can be caused on the frictional surface of 45steel and self-repair coatings generated while working conditions parameters suitable,the self-repairing coating has failed to be generated on the frictional surface of cast iron because of its metallographical structure and mechanical character.The research results of this paper have an important reference value for the further study on the friction and wear characteristic and probability of generating self-repair coatings of the cast iron lubricated in self-repairing additive, and also provide experimental reference for the application of additive on the friction pairs with cast iron.更多还原