Study On Aluminum Alloy P-MIG Welding Power And Arc Shape Based On DSP Control

Pulse-MIG welding with low heat input, high productivity, easy automation features is more suitable for aluminum welding. Pulsed MIG welding of aluminum alloy not only expands the scope of the welding current, but also improves the stability of arc, and can adapt to a variety of welding occasions. In recent years, the aluminum P-MIG welding technology has been widely used in the manufacture process. However, due to the special properties of aluminum, there are still some problems in welding applications. Pulse welding technology is complicated and control technology is also more complicated. How to control the various types of signals effectively and how to get a suitable current pulse wave have become very important. In this paper, we designed the aluminum alloy P-MIG digital control system based on DSP control technology. By the system, we can achieve the good pulse current waveform and the stable welding process. What is more, base current, peak current, peak time parameters can be manually adjusted. For the pulse current wave control, we achieve regulate pulse rising slope and falling slope independently.The characteristics of welding arc have an important impact on the chemical properties,the microstructure, geometry and gravity organizations. As there are many parameters in pulse welding process and these parameters have different influence on the welding arc, how to choose the suitable parameters is very important. Among the various pulse parameters, the peak current, base current and peak time parameters are the extremely important parameters. We have do some experiment about P-MIG welding of aluminum-magnesium alloy to analyze the influences of Aluminum P-MIG welding parameters on the welding arc. By regulating the different pulse parameters, we do the research about the influences of the peak current and base current on the arc. Under the conditions of different pulse parameters, the different arc shape could be acquired by high-speed photography collection system. The results shows that the arc length, width and arc square increases with peak current increasing, the base current is the parameters for keeping arc burning, and has an important impact on the arc stability.With the developing of waveform control technology of welding power, this study changes the current output waveform by regulating the slope of the pulse rising and falling, which is to study the influences of current output waveform change on the welding arc shape and arc stiffness. Pulse slope leading to change in pulse energy on pulse-on period, and change in pulse energy affects welding arc shape. At the same time, by regulating the slope of the pulse rising and falling, we can achieve to adjust the arc stiffness from hard norm to soft norm. Under the condition of soft norm, arc is dispersible with a bigger burning area, and the weld beam has greater width and penetration. Under the condition of hard norm, arc is very concentrated, and the weld beam has small width and penetration.