Viability of laser-based welding of T-joints made from 5xxx aluminium alloys

Abstract Aluminium is light, strong, durable and recyclable, which becomes more and more attractive for many industry sectors. The low density of aluminium, resulting in a high strength-to-weight ratio, makes it a favourable material for structures in a variety of applications, e.g., buildings, automotive, aerospace, helideck, living quarters and offshore and onshore wind etc. The increased use of aluminium in large structures will significantly contribute to achieving the climate goal through minimizing the greenhouse gas emission. Laser-based welding is an attractive alternative to arc welding due to much faster production rates and highly concentrated laser energy is more suitable to weld highly conductive metals. However, aluminium and its alloys suffer from softening and susceptibility to porosity. In this work, laser keyhole welding was used for double-sided welding of 10–20 mm 5xxx aluminium alloys as T-joints. Successful welds were produced using different heat inputs and using wobbling of laser beam providing a wide range of processing area. Low porosity levels were produced at optimized parameters. Despite softening up to 25% in weld zone, up to 95% joint efficiency was achieved.