Analysis of droplet transition features and weld formation in laser-MIG hybrid welding

Abstract

The image of laser-MIG hybrid welding process was collected by high-speed camera, the arc area and the barycenter of droplet were extracted by image processing method, the weld width and weld height were extracted from the 3D point cloud of weldment surface, and the relationship between droplet transition features, droplet velocity and weld formation were analyzed. Results show that the extremum of arc area and droplet transition period have the same change trend. The change of droplet velocity can effectively reflect the change of weld width. The decrease of arc length can increase the droplet transition frequency, speed up the droplet velocity and increase the weld width. The abrupt increase of arc length will increase the ratio of height to width, which reduce the welding quality.