LAUSR

The dynamic behavior of an arc plasma involves the complex heat and mass transfer process in the arc welding process, especially for pulsed gas metal arc welding (P-GMAW). The spectral diagnostics of the arc plasma is essential to both the validation of simulation results and the monitoring and control of the arc welding process. In this article, we studied the dynamic behavior and spatial spectral characteristics of the welding arc during the pulsed gas metal arc welding of the AA5083 aluminum alloy with an ER5183 wire using a high-speed camera and spectrometer. Based on the acquired spectra at different time points of the pulse, we calculated the plasma characteristics using the spectral lines emitted from the shielding gas and the metal vapor. The variation and spectral diagnosis of the arc indicated that the bright region was mainly caused by radiation from the metal vapor, which easily increased at the peak current. The measured arc temperature and electron density were elevated along with the welding current. Moreover, the ratio of metal vapor in the arc plasma also increased due to strengthened evaporation from the electrode. Along the horizontal axis, the arc temperature increased and reached a maximum in the central part of the arc. There was a potential local minimum near the electrode as the current increased. The drop of temperature near the electrode was mainly caused by the rapid evaporation and cooling effects of metal vapor.