复合工艺制备的表面微凹坑织构的摩擦性能研究

在构建的激光电化学复合微加工系统上,采用皮秒脉冲激光辐照与电解刻蚀复合加工方法在7075铝合金表面制备出不同尺寸的阵列凹坑微织构。采用共聚焦显微镜观测复合加工织构试样表面形貌,采用MFT-5000型RTEC摩擦磨损试验机研究润滑条件下凹坑织构的摩擦学性能,并探讨直径、深度、面积密度对减摩性能的影响。结果表明:复合加工工艺制备的表面微织构具有良好的表面形貌;润滑条件下材料表面的凹坑型织构能显著改善其摩擦学性能,相比光滑表面最高可降低摩擦因数30%;在实验参数范围内,凹坑的直径与面积密度对材料表面摩擦性能影响较大,凹坑深度对摩擦性能影响较小。

Tribological Properties of Micro pit Texture Generated by Composite Processing

Based on the established picosecond laser and electrochemical machining system,array pit micro structures of different sizes were fabricated on 7075 aluminium alloy surface by combined processing method of picosecond pulsed laser irradiating and electrochemical etching.The surface morphology of texture samples was observed by confocal microscopy,the tribological properties of micro pit texture samples under oil lubrication condition were investigated by using MFT-5000 RTEC friction and wear machine,and the influence of pit diameter,depth and area density on friction reducing performances was discussed.Results show that the surface micro texture prepared by the composite processing method has a good surface appearance.The pit textured surface can significantly improve the tribological properties of the material under oil lubrication conditions,and the friction coefficient of the textured samples can be reduced by up to 30% compared with that of the smooth samples.Within the experimental parameters,the diameter and area density of the pit have a great influence on the frictional properties while the pit depth has little effect.