Effect of current stability on surface formation of GMAW-based multi-layer single-pass additive deposition

During multi-layer single-pass additive manufacture based on gas metal arc welding, the formation of product surface is highly affected by the robot welding process status. The thermal history of the manufacturing process was recorded by a thermocouple, and the arc current was collected by a current sensor to investigate the relationship between arc current stability and manufacture workpiece surface formation. The empirical mode decomposition energy entropy of different Zas, which are related to the current stability and utilization of arc power, were calculated. The 3D geometric dimension information of the workpiece was scanned by a laser vision sensing system. Experimental results show the current signal of the arc can be used to assess process stability, current stability caused the temperature of the basement, and surface formation changed. The energy entropy of arc current increased with the increase of Zas. The unstable arc can take away much of the heat generated by the arc heat source leading to the increase of deposition height and side surface roughness.