Modeling of bead section profile and overlapping beads with experimental validation for robotic GMAW-based rapid manufacturing

Robotic gas metal arc welding enables the capacity of fabricating fully dense components with low cost in rapid manufacturing. During the layer additive manufacturing, the cross-sectional profile of a single weld bead as well as overlapping parameters is critical for improving the surface quality, dimensional accuracy and mechanical performance. This paper highlights an experimental study carried out to determine the optimal model of the bead cross-section profile fitted with circular arc, parabola, and cosine function, by comparing the actual area of the bead section with the predicted areas of the three models. A necessary condition for the overlapping of adjacent beads is proposed. The results show that different models for the single bead section profile result in different center distances and surface qualities of adjacent beads. The optimal model for the bead section profile has an important bearing on the ratio of wire feed rate to welding speed.