Advanced dual beam laser welding of zinc-coated steel sheets in lap joint configuration with zero gap at the interface

Abstract

A new concept for dual beam laser lap joining of galvanized steel sheets with zero gap at the interface is presented. This concept employs two laser beams with an angle between them. The new laser beam configuration is implemented by combining two laser focusing heads through use of a custom designed fixture. Welding trials were conducted with a robot by mounting the whole beam delivery set-up at the end of the robot arm. Excellent quality welds were obtained on a variety of zinc-coated sheet combinations. This paper focuses on the results obtained on 1.4/1.4 mm hot dipped galvanized steel sheets. The effects of various welding parameters were studied through both experimental trials as well as modeling of the keyhole geometry.