Correlation analysis in laser welding plasma

During the process of high power laser welding the interaction between laser beam and workpiece produces a plasma bunch, named plume which is ejected from the surface of the welded material. The efficiency of the welding process and the quality of the welded seams are influenced by the plasma plume which plays a fundamental role in coupling the incident radiation to the material. The aim of this work is to present an optical non-invasive spectroscopic approach for the investigation of plasma plume dynamics. In particular, we present data on optical spectroscopy of the plume produced during laser welding of aluminum-magnesium alloys of industrial interest. The dynamics of the plume during laser welding is investigated by performing a correlation analysis of the optical spectra (covariance mapping technique).