Power-arc model based adaptive arc length control of P-GMAW for Al–Mg alloy

It is essential to understand the power-arc model and the relationship of various parameters in pulsed gas metal arc welding (P-GMAW) process, in order to obtain stable arc length and droplet transfer. In this study, we analyzed the linear model of the GMAW process with some reasonable assumptions. A mathematical power-arc model of P-GMAW was established through an experimental statistical method by using a commercial welding power supply. Then, the mathematical model was applied combined with the adaptive arc length control strategy in the P-GMAW process of Al–Mg alloy by using the self-developed welding power supply. The experimental results indicated that the arc length of P-GMAW process for Al–Mg alloy kept uniform when using the experimental mathematical model and adaptive arc length control strategy. One drop per pulse (ODPP) droplet transfer mode was observed without spatters and cracks by carefully designing the preset parameters. The adaptive arc length control strategy showed good feasibility in Al–Mg alloy welding.