Abstract: The characteristics of single-layer multi-beads parts, produced by GTA-additive manufacturing, are first depicted in this paper. Results show that the morphology of single bead, the distance between beads (d) and the number of beads together determines the flatness of part’s surface. It means that if the welding parameters are fixed, the value of d influence the flatness on the largest extent. In order to obtain a proper value of d, a summary is made about this topic firstly. But in the application of aluminium alloy, some issues is found, including an error attributed to the approximation of welding beads’ profiles and a limitation in the parameters. Consequently, a modification is made and new computational model is established which is based on welding speed, wire feeding speed and bead height. Moreover, related experiments are carried out. Results show that, the new model can contribute to a proper value of d on widely parameters range.

Key words: additive manufacturing, single-layer multi-beads, distance between beads