【摘要】 摩擦副表面存在着与其润滑性能要求优化匹配的微观几何形貌。本文以发动机的气缸/活塞环为具体研究对象,基于气缸的摩擦磨损特征和润滑理论,对其表面的微观几何形貌进行了初步设计。采用半导体泵浦YAG固体激光器,在硼铸铁试样上进行了激光微造型加工工艺试验,系统研究了激光波长、激光功率、脉冲宽度、重复频率、扫描速度、重叠系数及辅助气体等,对金属材料激光微加工质量和效率的影响规律。并首次提出了“单脉冲同点间隔多次”激光微加工新工艺。最后,采用优化的激光参数组合,成功地在实际缸套内表面,加工出所设计的高质量表面微观几何形貌。更多还原

【Abstract】 On surface of frictional units,the regular micro-geometric structure which can be well matched to the needs of lubrication is obtained.In this paper,researching on the frictional units of cylinder liner/ piston ring,according to the property of wear-resistance of cylinder liner and the lubrication theory,the micro-geometric structure on surface of frictional units is preliminarily designed.A pulsed laser beams generated by Nd: YAG laser is adopted to do the experiment.According to the systemic research on laser micromachining on samples of boron cast iron,the influence rules of laser parameter and assistant condition(such as: laser wavelength,focus point width,average power,pulse width,repetition frequency,scan rate,overlap coefficient,assist gas pressure,etc.) on the quality of micro-structure has been obtained.Consequently,the new laser processing crafts of "single pulse at a time,repeat at intervals" has been presented by our research group.In the end,using the optimized combination of the laser parameters,the regular micro-geometric structure designed previously has been processed on the inner-wall of cylinder liner.更多还原