温度对MoDTC润滑条件下硬质涂层摩擦磨损性能的影响研究

发布时间：2018-07-04 16:41

  本文选题：CrN涂层 + TiN涂层　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：硬质涂层和良好的润滑状况是改善机械零件表面摩擦学性能的有效措施。本文针对润滑油及添加剂与硬质涂层复合作用的摩擦学机理研究不够深入的问题,考察了温度对CrN、Ti N和掺钨类金刚石(W-DLC)三种硬质涂层在聚α烯烃(PAO)及含二烷基二硫代氨基甲酸钼(MoDTC)润滑条件下的摩擦磨损性能的影响及减摩抗磨机理,具有重要的理论意义及应用价值。结果表明:(1)PAO润滑时,CrN/GCr15摩擦副的摩擦系数、CrN涂层磨损率及对磨球磨斑直径均随温度升高而增大。MoDTC的加入降低了摩擦系数,一定程度上减少了涂层及对磨球的磨损,且随温度升高,摩擦系数和涂层磨损率先减小后增大,对磨球磨斑直径先增大后减小,75oC时由于摩擦副表面的摩擦反应膜中MoS_2/MoO3比值较大而具有相对较好的摩擦学性能。磨损表面微观形貌分析表明,CrN涂层的磨损机制包括磨料磨损、疲劳磨损、氧化磨损及轻微的黏着磨损。(2)PAO润滑时,TiN/GCr15摩擦副的摩擦系数和TiN涂层磨损率随温度升高而增大,对磨球磨斑直径先减小在50 ℃之后也有所增加。MoDTC的加入降低了摩擦系数,提高了涂层和对磨球的耐磨性,随温度升高,摩擦系数先减小后增大,涂层磨损率逐渐增大,而对磨球磨斑直径整体呈减小趋势,在50oC时涂层具有相对较好的摩擦学性能,是由于该温度下摩擦副表面的摩擦反应膜中含有较大的MoS_2/MoO3比值及较多减摩的TiO_2和FeSx。磨损机制主要为磨料磨损、氧化磨损及高温下轻微的黏着磨损。(3)PAO润滑时,温度对W-DLC/GCr15摩擦副的摩擦系数影响不大,但涂层磨损率及对磨球磨斑直径随温度升高均有所减小,在高温下明显。MoDTC降低了摩擦系数,提高了涂层耐磨性但增加了对磨球的磨损,随温度升高摩擦系数、涂层磨损率和对磨球磨斑直径均先减小后增大,在125 ℃又有所减小,W-DLC涂层也在75oC时摩擦学性能较好,仍是因为该温度下摩擦副表面含有较多减摩的MoS_2及FeSx。不同的是W-DLC涂层的摩擦学行为还与其表面在不同温度下的石墨化程度有关。磨损机制为磨料磨损、氧化磨损及少量黏着磨损。
[Abstract]:Hard coating and good lubrication are effective measures to improve the tribological properties of mechanical parts. In this paper, the tribological mechanism of the compound action of lubricating oil and additives with hard coating is not sufficiently studied. The effects of temperature on the friction and wear properties of three hard coatings, CrNN- Ti N and W-DLC, under the lubrication conditions of polyolefins (PAO) and molybdenum dithiocarbamate (MoDTC), were investigated. It has important theoretical significance and application value. The results show that: (1) the friction coefficient of CrN / GCr15 friction pair decreases with the increase of temperature, the wear rate of coating and the diameter of grinding spot increase with the increase of temperature, and the wear of coating and grinding ball is decreased to some extent, and the wear of grinding ball increases with the increase of temperature, the results show that: (1) when PAO is lubricated, the friction coefficient of CrN / GCr15 friction pair increases with the increase of temperature. The friction coefficient and coating wear first decreased and then increased. The friction coefficient and coating wear increased first and then decreased at 75oC. The friction coefficient and coating wear increased firstly and then decreased to 75oC, which resulted in a relatively good tribological performance due to the larger ratio of MoS-2 / MoO3 in the friction reaction film on the surface of friction pair. The wear mechanism of CRN coating includes abrasive wear, fatigue wear, oxidation wear and slight adhesion wear. (2) the friction coefficient of TiN / GCr15 friction pair and the wear rate of tin coating increase with the increase of temperature when PAO is lubricated. The friction coefficient of the coating and the wear resistance of the grinding ball were improved by decreasing the diameter of the grinding spot at 50 鈩，

本文编号：2096693