Research on evaluation method of aluminum alloy pulse MIG welding stability base on approximate entropy

In order to evaluate the stability of the process of aluminum alloy pulsed Metal Inert Gas(MIG) Arc welding, an approximate entropy analysis has been done on voltage signal in the process of aluminum alloy pulsed MIG welding. The calculation and comparison of the approximate entropy on voltage signal under different welding parameters, such as welding speeds, wire feed speeds, duty cycle and so on, shows that the approximate entropy of voltage can reflect the stability of the process of aluminum alloy pulsed MIG welding. The results show that the smaller the average value of approximate entropy, the more stable the welding process will be. Otherwise, the welding process is unstable while the average value is bigger.