利用皮秒激光加工不锈钢, 采用激光共聚焦显微镜对加工后形貌和质量进行观察与表征, 研究激光能量密度和扫描速度对孔形貌与质量的影响, 以及激光束与工件夹角对锥度的影响。结果表明, 随着能量密度的增大, 皮秒激光加工的热影响越大, 孔径增大, 锥度会减小且孔入口圆度降低, 孔出口圆度随着能量密度增大而增大, 然后趋于稳定, 最后又会下降。扫描速度对于孔入口处的孔径及其圆度都不会产生影响, 圆度保证在98%左右, 随着扫描速度增加, 出口处的孔径先减小后趋于稳定, 锥度增大后稳定在4.0°左右, 出口处的圆度增大后稳定在97%～98%。锥度实际值与工件旋转角度呈非线性关系并给出了函数表达式。

The stainless steel is machined with the picosecond laser, and the morphologyandquality are characterizedby theconfocal microscopy. The effect of laser fluence and feeding speed on the morphologyandquality of micro-holes, and the effect of angle between laser beam and workpiece on taper are studied. The results show that the heat effect and diameter of micro-holes are increasing, and the taper and the circularity at entrance are decreasing as the increasing of the laser fluence. The circularity at exit increases as the laser fluencegrows, then it tends to be stable till the decreasing. The circularity at entrance keeping on 98% and the diameter at entrance aren’t affected by the feeding speed. The diameterat exit decreases as the feeding speed grows, then it tends to be stable.When the feeding speed increases, the conicity increases to 4°, the circularity at exit increases to 97%～98%. At last, the nonlinear correlation between actual conicity and rotation angle of workpiece is demonstrated, and the function is given.