Theoretical Approaches to Erosion and Wetting Phenomena during Laser Brazing Process

The theoretical approaches to the erosion and wetting/flowing phenomena during the laser brazing process were made by the computer simulation. The erosion kinetics of the Inconel 600 base metal was investigated using Au-18%Ni filler metal. The erosion profile during the laser brazing was estimated by applying the additivity rule to the Nernst-Brunner theory based on the measured thermal cycle of the filler metal droplet. The computed erosion profiles in the laser brazed joints were fairly consistent with the experimental ones. The wetting and flowing of the melted Au-18%Ni filler metal on the Inconel 600 butt joint during the laser brazing were analyzed by the metal flow model. The filler metal droplet wetted and spread on the base metal and simultaneously infiltrated into the joint gap with the lapse of time. In the single beam brazing, the filler metal did not infiltrate into the 0.1mm wide joint gap at the completion of brazing, however, the filler metal could be filled up in it in the tandem beam brazing.