The Study Of PMIG Equipment And Process Welding Process For Aluminium Alloy

The pulse MIG welding is a high-efficiency and high-quality welding method. The welding technique has many advantages such as good arc axial property, low spatter and good weld beam shape. Especially, The pulse MIG welding has wide range of current, controllable heat input and full position availability. The ability to extend spray arc welding down to lower welding data is particularly suitable when welding materials such as stainless steel or aluminum. It becomes possible to weld thin materials, or to perform positional welding, with better results than would be obtained with short arc welding.Arc-length control is the core of welding process stability. A new arc-length synchronization pulse control method is presented and the higher arc-length adjustment performance is achieved within a wide range. For sheet metal aluminum welding, timely adjustment and effective control of arc-length is very important in order to avoid melt back events in the GMAW mass production in an automated production line. This paper found an interesting solution to the problem, enabling both self correction and control of the pulse parameters to be used together. This involves a CCCC characteristic, i.e. constant current during both the pulse and the background current period between pulses. The arc voltage is measured at the end of the current pulse, thus providing a signal to indicate the arc length. If the arc is too short, the pulse frequency is increased, which is done in practice by maintaining the pulse width but reducing the background current duration. The control performance and corresponding process results improved greatly.The experimental results validated that the desirable control performance is achieved with the repeatable pulse current waveform, high-speed and stable arc-voltage adjustment. Even if arc length varies with higher frequency and large amplitude in the welding process is very stable. Spatter can be avoided with new arc length control design and suitable process parameters. In addition, arc ignition program is designed and the stable arc ignition process is achieved.