蛇纹石润滑油添加剂摩擦反应膜的力学特征与摩擦学性能

Mechanical and Tribological Properties of Tribofilm Derived from Serpentine Mineral Lubricant Additive

文中考察了变载、变速条件下表面修饰蛇纹石超细粉体作为矿物基础油添加剂的摩擦学性能,利用扫描电镜、能谱仪、纳米压痕仪等对比分析了蛇纹石添加剂形成的摩擦反应膜和基础油润滑下的磨损表面微观形貌、元素分布及微观力学性能.在此基础上,通过改变旋转滑动试验过程中的载荷/速度比,建立了基础油/摩擦反应膜和基础油/普通磨损表面润滑体系的Stribeck曲线.结果表明:蛇纹石超细粉体作为润滑油添加剂形成的摩擦反应膜具有较高的硬度和近似于金属材料的弹性模量,氧化物颗粒的嵌入进一步改善了摩擦反应膜的微区纳米力学性能,同时膜层的多孔结构可起到储油和捕获磨粒的双重作用,从而使摩擦反应膜在边界和混合润滑状态下表现出优异的摩擦学性能.

The tribological properties of uhrafine surface - coated serpentine powder as a mineral oil additive were evaluated under varying speed and load. The morphology and element distribution of worn steel surfaces lubricated by base oil and base oil containing serpentine additive were analyzed using scanning electron microscope and energy dispersive spectrometer. The micro -mechanical properties and scratch resistance of the normal worn surface （lubricated by base oil） and the tribofilm （lubricated by base oil containing serpentine additive） were analyzed using a nano - indentation tester. Furthermore, Stribeck tests for point contacts were carried out to compare the tribological properties of the oil/normal worn surface system and the oil/tribofilm system in different lubrication regimes. Results show that serpentine additive gives birth to a porous oxide tribofilm with a high hardness and a Young＇ s modulus similar to that of steel. Besides, embedded oxide particles can further improve nano - mechanical properties of the tribofilm, while porous tribofilm can act as an oil reservoir to retain oil and capture wear particles simuhaneously. As a result, the tribofihn possesses excellent tribological properties under boundary and mixed lubrication conditions.