铝合金飞秒激光单步法和三步法旋切打孔技术研究  

Femtosecond Laser Single-step and Three-step Trepanning Drilling Technology of Aluminum Alloy

作　　者：任云鹏[1] 程力 周王凡 陈燕[2] 何坤 涂新诚 叶云霞[1] 任乃飞[1] Ren Yunpeng;Cheng Li;Zhou Wangfan;Chen Yan;He Kun;Tu Xincheng;Ye Yunxia;Ren Naifei(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013 [2]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《中国激光》2022年第22期220-229,共10页Chinese Journal of Lasers

基　　金：中国博士后科学基金(2020M671409);江苏省博士后科学基金(2020Z030)。

摘　　要：铝合金由于其优良的物理化学性能,在工业生产中得到了广泛应用,但铝合金的高反射率和高热导率限制了激光加工技术在铝合金精密加工中的应用。采用控制变量法研究了铝合金单步法旋切打孔技术中的激光重复频率、扫描次数、扫描速度、进给次数对微孔出入口形貌和锥度的影响规律。针对铝合金单步法旋切打孔中存在的锥度大和出入口形貌差等问题,提出了三步法旋切打孔方法。结果表明,该方法可以有效地减小微孔的锥度,改善出入口形貌,减少孔口周围的飞溅物堆积。主要原因是该方法可以有效地促进打孔过程中熔渣和等离子体的排出,减少其对激光能量的扰动,提高了激光能量的稳定性和均匀性。Objective With the rapid development of modern industry, aluminum alloy has been widely used in industrial production due to its excellent physical and chemical properties. Meanwhile, the preparation of high-quality microholes in aluminum alloys is in high demand. Laser drilling technology, when compared with other traditional microhole machining techniques, has the advantages of high processing accuracy and efficiency, good flexibility, and no tool loss. However, the high reflectivity and thermal conductivity of aluminum alloys make it challenging to prepare high-quality microholes. Hence, it is crucial to study the influence of laser parameters on microhole morphologies and tapers and develop laser drilling technology for microholes in aluminum alloys.Methods In this study, we use a femtosecond laser to drill microholes with a diameter of 200 μm in a 1 mm thick 1060 aluminum alloy. First, the influence of the laser repetition rate, scanning time, scanning speed, and feed time on microhole morphologies and tapers is studied using the control variable method. Then, based on the single-step trepanning drilling method [Fig. 2(a)], a three-step trepanning drilling method [Fig. 2(b)] is proposed to solve the problems of big taper and poor entrance and exit morphologies. The three circles are set as one ring in the three-step trepanning drilling method. The innermost circle(C1) is first scanned clockwise, and the laser moves toward the first ring’s outer circle(C3). After the first layer scanning, the laser feeds down a distance and the above process of C1--C3 is repeated until the center perforated hole forms. Subsequently, the laser is focused on the C4--C9 circles to complete the second and third rings similarly and finally the microhole processing is finished. In the three-step trepanning drilling, the drilling process is divided into three steps: the first ring is used to form the center microhole, the second ring is used to widen it, and the third ring is used to improve the hole morphology [Fig. 3(b)]. The e

关 键 词：激光技术 飞秒激光 旋切打孔 铝合金 锥度 

分 类 号：TN249[电子电信—物理电子学]