激光处理合金铸铁的摩擦磨损性能研究

利用SRV摩擦磨损试验机考察了激光微精处理合金铸铁的摩擦磨损性能,利用扫描电子显微镜分析了激光淬火组织剖面微结构及磨斑表面形貌,同时采用X射线光电子能谱仪(XPS)分析了激光微精处理合金铸铁的表面成分及典型元素化学状态.结果表明,激光处理的合金铸铁具有理想的表面形貌和较高的表面硬度,在含添加剂的油润滑条件下,其抗磨性能大幅度提高.3种添加剂的承载能力顺序为二烷基二硫代磷酸锌＞磷酸三甲酚酯＞硫化异丁烯.二烷基二硫代磷酸锌与激光微精处理的合金铸铁磨痕表面发生摩擦化学作用,形成由微量硫酸盐、磷酸盐及相应的氧化产物组成的表面润滑与防护薄膜,从而使得激光微精处理合金铸铁的摩擦磨损性能明显改善.

Study of the Friction and Wear Behavior of Laser Micro-Precisely Treated Alloy Cast Iron under Lubrication

Alloy cast iron specimens were treated making use of laser micro-precision technology. The friction and wear behavior of the modified samples was investigated using an SRV test rig. The microstructure and worn surface morphology of the treated samples were observed using a scanning electron microscope. The chemical states of the typical elements on the worn surface of the laser micro-precision treated alloy cast iron specimens were determined by means of X-ray photoelectron spectroscopy. It was found that the treated alloy cast iron specimens had improved surface topography and significantly increase hardness and wear resistance. At the same time, the wear of the treated alloy cast iron samples was greatly decreased under the lubrication of liquid paraffin containing various extreme pressure and antiwear additives. This was because the specific surface morphology of the treated samples helped to store the lubricating oil and make full use of the friction-reducing and antiwear ability of the lubricant. The load-carrying capacity and antiwear ability of the tested base oil and additives were ranked as ZDDP>TCP>SO>liquid paraffin. The reason lay in that ZDDP was able to form a lubricating and protective film on the alloy cast iron surface by way of physico-chemical adsorption and tribochemical reaction, which contributed to greatly increasing the load-carrying capacity and antiwear ability of the lubricant.