激光填丝焊焊丝熔入行为研究

Melting behaviors of filler wire during laser welding

激光填丝焊接技术因其特有的优点提高了其焊接经济性,在增材制造和修复领域具有广阔的应用前景。然而焊丝熔入行为对焊接过程的稳定性和焊缝成形质量有很大影响。基于高速摄像采集技术和焊接工艺试验系统研究了焊丝熔入行为和焊缝成形质量之间的内部联系。结果表明,焊丝送进位置和送丝速度是影响焊丝加热熔化机制和液态金属过渡行为的关键因素;根据光丝间距的变化液态金属过渡行为可分为大滴过渡、液桥过渡和铺展过渡3种形式,其中液桥过渡时焊接过程最稳定且焊缝成形质量最好。

Laser welding with filler wire has made it possible to improve the economy of welding due to its properties. Therefore ,it has broad application prospects in the additive manufacturing and repairing fields. However, the melting behaviors of filler wire seriously affects the stability- of welding process and the quality of weld. Based on high-speed camera acquisition technology- and welding process test system,this paper focuses on the systematic study of the internal connections between melting behaviors of filler wire and weld quality-. The results show that position of wire feeding and the wire feeding speed have a great inffluence on the melting mechanisms and transfer behaviors of filler wire. According to the change of distance between laser spot and filler wire,transition behaviors of molten metal can be decomposed into globular transition behavior,liquid-bridge transition behavior and spreading transition behavior. The stable welding process and the well-formed deposition layer can be obtained when liquid metal was transferred into welding pool with liquid-bridge.