圆凹坑-球凸复合织构的激光铣削加工及其摩擦学性能

Laser Milling Processing and Tribological Performance of Circular-Concave-and-Spherical-Convex Compound Texture

圆凹坑织构被广泛应用于各类摩擦副以改善摩擦学性能。为进一步提高圆凹坑织构的摩擦学性能,鉴于球凸织构能产生优异的动压效应,提出圆凹坑-球凸复合织构,使球凸在圆凹坑内产生二次动压来增强圆凹坑织构的减摩效果。为加工出圆凹坑-球凸复合织构,分析其激光铣削加工工艺,并研究复合织构在销-盘面接触下的摩擦磨损特性。结果表明,在变角度直线扫描路径,单脉冲能量23μJ和光斑间距2μm下激光能量分布较均匀,复合织构的加工误差较小。合适的球凸高度可大幅提高圆凹坑织构的摩擦学性能,在一定条件下,圆凹坑-球凸复合织构较圆凹坑织构平均摩擦系数下降41.0%。

The circular concave texture is widely applied in various friction pairs to improve the tribological performance.In order to further improve the tribological performance of circular concave texture,considering that the spherical convex texture can generate the excellent hydrodynamic lubrication effect,the circular-concave-and-spherical-convex compound texture was proposed.The spherical convex was utilized to generate second hydrodynamic pressure in the circular concave,thereby increasing the friction reduction.In order to fabricate the circular-concave-and-spherical-convex compound texture,the laser milling processing was studied,the friction and wear properties of compound textures were evaluated by pin-on-disk experiments.The results show that the laser energy distribution is more uniform when the liner scanning path is variable angle,the single pulse energy is 23μJ and spot spacing is 2μm,and thus the machining error of compound texture is small.The compound texture with appropriate spherical convex height can greatly improve the tribological performance of circular concave texture.Under certain conditions,the average friction coefficient of the circular-concave-and-spheric al-convex compound texture is 41.0%lower than that of the circular concave texture.