【摘要】 在 12 5℃和 32 0℃下 ,以全配方矿物基 SJ/5 W- 30型发动机油作为基础润滑油 ,考察了油溶性有机钼添加剂Mo DTC与 Mo DTP对灰铸铁缸套 /喷钼活塞环摩擦学行为的影响 .结果表明 :Mo DTC可以改善基础油的减摩抗磨性能 ,而 Mo DTP仅表现出一定的抗磨作用 ;试验温度对缸套 -活塞环的摩擦磨损性能具有重要影响 .X射线光电子能谱分析表明 :缸套磨损表面主要含有铁氧化物、氧化钼、硫化铁、二硫化钼以及磷酸盐等 ,其含量与添加剂类型和摩擦磨损试验温度有关 .12 5℃下在缸套磨损表面上减摩组分 Mo S2 和其它耐磨组分的含量较高 ,这是 Mo DTC具有较好减摩耐磨性能的主要原因 .更多还原

【Abstract】 The tribological behavior of Mo sprayed piston ring sliding against grey cast iron cylinder liner under the lubrication of a fully formulated petroleum based engine oil SJ/5W 30 containing molybdenum dithiocarbomate (MoDTC) or molybdenum dithiophosphate (MoDTP) was investigated with an Optimol SRV test rig. The testing temperatures were controlled at 125 ℃ and 320 ℃ to simulate the real engine operating conditions.The worn surfaces of the piston ring and cylinder liner were observed and analyzed by means of scanning electron microscopy (SEM) and X ray photoelectron spectroscopy(XPS). It was observed that the frictional behavior of both MoDTC and MoDTP depends heavily on the experimental temperature; MoDTC is effective in decreasing the friction coefficient and wear rate at a relatively extended test duration while MoDTP shows friction reduction ability only at relatively high temperatures. It can be seen from the SEM observations of the worn piston ring and cylinder liner surfaces that the set test temperature range has also strong impact on both the wear severity and the wear mechanisms in the contact surface. When it rises from 125 ℃ to 320 ℃, the wear becomes more serious, and the wear mechanism changes from abrasion to adhension. In addition, the chemical interaction between the lubricant containing organo molybdenum and the tribocontact surfaces plays a crucial role in friction reducing or antiwear film formation, which is dependent on the tribochemical characteristics of the active ferrous materials and the applied friction modifiers such as MoDTC or MoDTP. XPS analysis of the worn cylinder liner surfaces indicates that the resultant tribochemical films are mainly composed of iron oxides, molybdenum oxide, iron sulfide, molybdenum disulfide, and zinc and iron phosphates. The proportion of these species is a function of both the specific friction modifiers used and the experimental temperature. It is supposed that the better friction reduction and wear resistant actions of MoDTC at 125 ℃ is attributed to the higher content of MoS 2 and other wear resistant compounds generated on the worn cylinder liner surfaces.更多还原