【摘要】 针对0.5 mm厚TA1钛合金薄板，采用点环扫描激光的新型焊接方式，研究了工艺参数对焊缝成形与组织性能的影响。采用单因子试验方法，每次仅改变一个参数，固定其它参数不变。各工艺参数不变时的基准数值分别为：中心功率P_z=800 W，外环功率P_w=1 200 W，焊接速度v=100 mm/s，扫描频率F=300 Hz。改变某一个参数时，其变化范围分别为：中心功率P_z=200～800 W，外环功率P_w=1 200～1 800 W，焊接速度v=40～100 mm/s，扫描频率F=100～400 Hz。研究结果表明：点环扫描激光相比非扫描激光，兼具大熔宽与浅熔深的特点，非常适合薄板焊接；相比普通扫描激光，不仅熔深与熔宽更大，同时焊缝表面成形更光滑、美观，因焊缝余高凸起造成的应力集中也更小。点环扫描激光焊缝显微组织为α相。点环激光的中心功率与外环功率变化对焊缝显微组织、接头抗拉强度与延伸率的影响不显著。焊缝抗拉强度达到母材的95%～96%，延伸率达到母材的54%～60%。更多还原

【Abstract】 A new welding method using adjustable-ring mode (ARM) scanning laser was employed to weld 0.5 mm thick TA1 titanium alloy thin sheets.Effects of process parameters on weld formation,microstructure and mechanical properties were studied.A single factor method was adopted in the experiment.One parameter was changed at a time,while other parameters remained unchanged.The values of the process parameters were as follows: the central power P_z=800 W,the ring power P_w=1200 W,the welding speed v=100 mm/s,and the scanning frequency F=300 Hz.When the parameters were changed,the variation ranges are distributed as: the central power P_z=200～800 W,the ring power P_w=1 200～1 800 W,the welding speed v=40～100 mm/s,and the scanning frequency F=100～400 Hz.The results show that compared with non-scanning laser welding,the ARM scanning laser leads to broader bead width and larger penetration,which is highly suitable for thin sheet welding.Compared with conventional scanning laser welding,the ARM scanning laser not only leads to larger bead width and depth,but also produces smoother bead formation and prettier weld appearance,with smaller stress concentration due to lower weld reinforcement.The microstructure of the ARM scanning laser weld metal consists of α phase.The influence of the central power and outer ring power of the ARM laser have insignificant effects on the microstructure,tensile strength and elongation.The tensile strength of the welded joints reaches 95%～96% of the base metal,while the extensibility achieves 54%～60% of the base metal.更多还原