CFRP复材飞秒激光小孔加工工艺研究

Technological investigation of femotosecond laser drilling of CFRP composite

飞秒激光有着极窄的脉宽、极高的峰值能量,因此具有加工范围广、加工质量好等优势。利用飞秒激光对CFRP复合材料进行小孔加工试验,研究了光斑局部填充和全填充两种方式对Φ3 mm小孔加工的影响。通过光学显微镜、工业CT等检测手段对试件的小孔加工进行检测,分析小孔进出口形貌以及内壁锥度,对比讨论了不同填充方式对材料去除的影响。试验结果表明,全填充的排屑条件好于局部填充,因此更容易加工出通孔;局部填充易导致光束向底部反射以及热量聚集所致的材料去除,因此加工出的通孔锥度较小。扫描速度越小,孔的锥度越小,反之扫描速度越大,孔的锥度越大。填充间距影响着激光的输入能量密度,因此填充间距对小孔加工的深度有直接影响,对小孔入口直径以及小孔锥度的影响较小。

Femtosecond laser machining has advantages of wide processing capability and good processing quality due to extremely narrow pulse and high peak energy.In this paper,femtosecond laser is applied to drill small holes on CFRP composite materials using different spot filling patterns.The effect of the partially filling and full filling on the drilling ofΦ3 mm holes has been investigated.Optical microscope and industrial CT have been used to measure machining results.The morphology and wall taper angle have been analyzed,and effects of different spot filling patterns on material removal also been compared and discussed.The result shows that full filling pattern can easily form through holes;however,the partial filling pattern can achieve holes with smaller taper angle.The smaller the scanning speeds are,the smaller the taper of the hole is;on the contrary,the higher the scanning speeds is,the greater the taper of the hole is.The filling distance affects the input energy density of the laser,so the filling distance has a direct effect on the depth of the small hole processing,and less effect on the small hole entrance diameter and the small hole taper.