The influence of wire feeding speed during laser welding with a filling wire was investigated by high-speed imaging and mechanical analysis of the droplet. A force relationship was found to analyze the droplet transition behavior at the end of the welding wire in the narrow-gap groove. Welding defects, mainly including nonfusion and porosity, were studied to reveal the formation mechanism and propose affective solutions. In this paper, it was found that the droplet transition was determined by the position of the melting end of the wire in the narrow-gap groove under the same parameters. The sidewall transition, the liquid bridge transition, and the spreading transition were found at different wire feeding speeds. As the wire feeding speed increases from 3 to 6 m/min, the weld depth increased 40%, the maximum weld width decreased 16%, and the minimum weld width increased 8%. More nonfusion and porosity defects and poor weld formation would appear at excessive wire feeding speed.

中文翻译：

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送丝速度对激光填丝焊窄间隙接头熔化行为及形成的影响

通过熔滴的高速成像和力学分析，研究了填充焊丝激光焊接过程中送丝速度的影响。发现了一种力关系来分析窄间隙坡口中焊丝末端的熔滴过渡行为。研究了焊接缺陷，主要包括未熔合和气孔，以揭示形成机制并提出有效的解决方案。在本文中发现，在相同参数下，熔滴过渡是由焊丝熔化端在窄间隙槽中的位置决定的。在不同的送丝速度下发现​​了侧壁过渡、液桥过渡和铺展过渡。随着送丝速度从3增加到6m/min，焊缝深度增加40%，最大焊缝宽度减少16%，最小焊缝宽度增加了8%。送丝速度过快会出现更多的未熔合和气孔缺陷以及焊缝成形不良。