Wang Xiao, Liu Baoguang, Liu Wei, Zhong Xuejiao, Jiang Yingjie, Liu Huixia
School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China.
Materials (Basel). 2017 Jan 1;10(1):22. doi: 10.3390/ma10010022.
To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA) is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s) and type II (pulse frequency and the duration is 5 Hz, 3 s)) to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results.
为满足轻型汽车中聚合物连接的需求，利用Nd:YAG脉冲激光对聚甲基丙烯酸甲酯（PMMA）的激光透射点焊进行了研究。研究了峰值电压、离焦距离和焊接类型（I型（脉冲频率和持续时间为25Hz，0.6s）和II型（脉冲频率和持续时间为5Hz，3s））这三个变量对焊接质量的影响。结果表明，在相同峰值电压和离焦距离的情况下，I型的气泡数量明显多于II型。I型的失效模式是基板沿焊点断裂，且I型的连接强度大于II型。I型的熔池直径与深度比明显大于II型。可以看出，熔池直径与深度比和焊接强度之间存在一定关系。通过有限元模拟，I型的熔池比II型更细长，这与实验结果大致相同。
