不同结构层状硅酸盐矿物作为润滑油添加剂的摩擦学性能

Tribological Performance of Phyllosilicate Minerals as Lubricating Oil Additives

采用UMT-3型往复磨损试验机考察了海泡石、凹凸棒石、蛇纹石3种不同结构天然层状硅酸盐矿物粉体作为润滑油添加剂的摩擦学性能。借助扫描电子显微镜、能量色散谱仪及X射线光电子能谱仪等对磨损表面进行了形貌和成分分析,探讨了硅酸盐结构与其摩擦学性能及减摩润滑机制之间的关系。结果表明:3种硅酸盐粉体作为润滑油添加剂均具有较好的摩擦学性能,与基础油润滑下相比,可降低平均摩擦因数2.4%~25.5%,减少磨损体积37.4%~56.2%;含硅酸盐油样作用下的摩擦表面由于生成了由铁的氧化物、氧化硅和石墨等摩擦反应产物构成的复合摩擦反应膜,导致其具有良好的减摩润滑性能;相对蛇纹石而言,凹凸棒石和海泡石由于具有纤维状的形貌特征,同时独特的TOT型晶体结构使其更易在摩擦过程中形成高含量氧化物和石墨,从而在高载荷条件下具有更优异的摩擦学性能。

Tribological properties of three different silicate natural mineral powders,i.e.,sepiolite,attapulgite and serpentine as lubricating oil additives were investigated in an UMT-3 tribometer.The morphologies and elemental components of the worn surfaces were analyzed by scanning electron microscopy(SEM),energy dispersive spectrometry(EDS)and X-ray photoelectron spectroscopy(XPS).The relationship between the structure of silicate as well as its anti-wear and friction reducing mechanism were discussed.The results indicate that all three silicate powders can provide excellent tribological properties as lubricating oil additives.Compared to 500 SN,these additives have lower friction coefficients and wear volumes,which are 2.4%-25.5%and 37.4%-56.2%,respectively.The friction films are formed with iron oxide,silicon oxide and graphite when silicate powder additives are used,providing the excellent anti-wear and friction reducing properties.Unlike serpentine,attapulgite and sepiolite have a fibrous structure,and the TOT crystal structure is easier to form the frictional films with more oxides and graphites,leading to the superior tribological performance at a higher load.