High power CO2 laser welding of Al alloy plates

Abstract

Using a high power pulse transverse flow CO2 laser developed in our lab, a series of thin Al alloy plates were successfully welded. Effects of processing parameters (beam quality, laser power, welding speed and assisting gas et al.) on weldability of Al alloy plates were given. A key technique, artificial keyhole caused by the gap between two Al alloy butt plates is successfully used, which helped to break through their high reflectivity at 10.6μm wavelength and enhanced the energy coupling efficiency. The weld thickness of Al alloy plates reached 4mm with 3 kW CO2 laser average output power. Microhardness and tensile tests showed that for some Al alloys, mechanical properties of the welds could be near or equal to base material with the artificial keyhole technique and suitable processing parameters.