激光表面织构形状参数对钛合金摩擦学性能的影响

针对钛合金耐磨性差的问题,利用激光技术在TC4钛合金样品表面刻蚀出具有不同形状、间距和宽度(直径)的织构,基于CSM球盘式摩擦磨损试验机研究织构形状参数对钛合金在油润滑条件下摩擦学性能的影响。利用扫描电子显微镜(SEM)观察钛合金表面织构的微观形貌及磨痕形貌,利用白光干涉仪测试表面织构和磨痕的三维轮廓并通过计算得到磨损率。结果表明,网格型织构的摩擦因数比沟槽型和点阵型织构更小并且更稳定。织构的间距和宽度(直径)等形状参数显著影响钛合金的磨损性能。原始表面抛光钛合金样品磨损率高于表面织构处理后样品,原始钛合金样品的磨损机制主要为磨粒磨损和粘着磨损,而由于表面织构能起到收集磨屑,储存润滑油的作用,从而显著提升了钛合金的耐磨性。

Effects of Shape Parameters of Laser Surface Texture on Tribological Performance of Titanium Alloy

Aiming at the poor tribological performance of titanium, textures in different shape, interval and width (diameter) were produced on the TC4 titanium surface by laser system, and the effects of different shape parameters on the tribological properties of titanium alloys were investigated using CSM ball-on-disc tribometer. The microtopography and scratch morphology of titanium alloys were characterized by SEM. The 3D profiles of the texture and scratch were measured by WLI white light interferometer. The results show that the friction coefficient of grid texture is smaller and more stable than those of the dimple texture and groove texture under the same experimental conditions. The shape parameters including interval and width (diameter) of texture have a significant effect on the tribological properties of titanium alloys. The unit wear rates of dimple texture are the largest, and followed by groove texture, while grid texture has the minimum unit wear rate. The wear rates of polished surface are larger than that of textured surface. The main wear mechanism of titanium alloy is abrasive wear and adhesive wear. The surface texture can significantly enhance the abrasive resistance of titanium alloys because of the entrapment of wear debris and reserve of lubricants.