Development of approaches to real-time optical diagnostics for laser weld formation process using laser emission spectroscopy

Abstract

Welding of metals is subject to various random processes that degrade the quality of the weld, ranging from the presence of inhomogeneities in the metal to spontaneously occurring pulsating processes. Pre-weld destructive testing cannot eliminate the presence of inhomogeneities and is ineffective for spontaneous deviations in the welding process. Therefore, the development of new approaches for real-time diagnosis of the laser welding process is particularly relevant today, especially with the widespread implementation of fiber lasers. The objective of this study was to develop approaches for optical diagnostics of the process of forming heterogeneous material based on laser emission spectroscopy. An experimental setup was created to develop approaches for optical diagnostics of the process of forming heterogeneous material, which is a critical task for additive technologies and laser welding. It was demonstrated that for industrially relevant aluminum alloys 1420, 1580, AMG (Russia), it is possible to record the spectra of the gas-plasma plume that occurs when laser radiation interacts with the metal surface. These spectra depend on the radiation exposure conditions and reflect the processes of atom and molecule evaporation from the molten pool. Further research will allow establishing the nature of this connection and developing optimal modes for technological processes, enabling real-time control of these processes.