钛合金薄板激光反射叠加深熔焊成形工艺优化

Process optimization of laser reflection-induced superimposition deep-penetration welding for titanium alloy sheet

针对现有薄板激光深熔焊方法的不足,提出了一种新的薄板激光深熔焊方法—激光反射叠加焊.基于正交优化和单因素优化试验,以焊缝形貌特征为评价指标,对钛合金薄板激光反射叠加焊接成形工艺参数进行了优化.结果表明,扫描速度是其主要影响因素,离焦量次之,而激光功率的影响则很小;随着扫描速度的减小,焊缝宏观形貌由倒V形依次转变为近X形、H形和Y形.在文中试验条件下,优化后的激光焊接成形工艺参数为功率500W、扫描速度30 mm/s、离焦量-0.5 mm,在此工艺参数下获得了背宽比几乎等于1且焊缝宽度一致性好的H形焊缝,而且施焊背面几乎不存在焊缝凹陷缺陷.

A novel sheet metal laser deep-penetration welding method,namely laser reflection-induced superimposition welding,is presented to overcome the shortcomings of existing methods. Based on the orthogonal optimization experiment and single factor optimization experiment,the welding parameters of titanium alloy sheet reflection-induced superimposition welding is optimized with taking weld-morphological characteristics as evaluation indexes. The results show that welding speed has the greatest influence,followed by defocusing amount,and the influence of laser power is very small. With the decrease of welding speed,the cross-sectional morphologies of welds transformed from inverted V shape to near X shape,H shape,and Y shape. With the experiment conditions in this work,the optimized parameters of laser welding are 500 W laser power,30 mm / s welding speed,-0. 5 mm defocusing amount. The H-shaped weld whose weld width back to surface ratio almost equals to 1 can be obtained with the optimized parameters,and there is no pitting defect on the back of welds.