PFPE脂润滑2Cr13钢摩擦副的真空摩擦磨损行为研究

利用销-盘式摩擦磨损试验机对PFPE脂润滑2Cr13钢摩擦副进行了不同滑动时间的真空滑动摩擦磨损试验.采用扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)和傅里叶变换红外光谱(FTIR)分别对磨损表面的形貌、化学状态及润滑脂的结构和成分进行了系统分析.结果表明:随着滑动时间的增加,由微切削磨损、轻微腐蚀磨损向严重腐蚀磨损、轻度局部剥落继续向严重黏着磨损、严重局部剥落的严重复合磨损转变.在真空摩擦过程中PFPE润滑脂主要以物理退化为主,即润滑脂中基础油和增稠剂的相对比例发生变化.同时,PFPE润滑脂与2Cr13钢在摩擦过程中发生化学反应,生成具有催化作用的Fe F3.但由于所生成的Fe F3量较少,并未使PFPE润滑脂发生化学降解.

Friction and Wear Behavior of PFPE Grease-Lubricated 2Cr13 Steel Friction Pair in Vacuum

The friction and wear tests of the perfluoropolyether (PFPE) grease-lubricated 2Cr13 steel friction pair with different sliding time were conducted on a pin-on-disk type tribometer in vacuum. The morphologies of the worn surfaces were observed by scanning electron microscopy.The chemical states of typical elements on the worn surfaces and PFPE grease were examined by means of X-ray photoelectron spectroscopy. The chemical structure of grease before and after wearing was analyzed by Fourier transform infrared spectroscopy. Experimental results show that the wear mechanisms of PFPE grease-lubricated 2Cr13 steel showed a transition from a mild wear including a mild cutting and a corrosive wear to a severe corrosive wear and a mild local delamination, then to a severe mixed wear involving with a severe adhesive wear and a local delamination with increasing the sliding time. The PFPE grease occurred physical degradation during wearing in vacuum, namly change in the ratio between the thickener and the base oil of the PFPE grease. Tribochemical reactions occurred between the PFPE grease and 2Cr13 steel during wearing in vacuum to produce FeF₃. The quantity of FeF₃ as a catalyst was too low to promote the chemical degradation of PFPE grease.