Laser brazing of a steel/aluminium assembly with hot filler wire (88% Al, 12% Si)

The main problem in joining steel to aluminium by a thermal process (e.g. TIG, MIG) is the formation of brittle intermetallic phases, that causes the mechanical performance of the assembly to be poor. A laser beam, however, can localize the fusion and inhibit the formation of these phases. This article presents a feasibility study for steel/aluminium assemblies with filler wire of 88% Al and 12% Si. Analysis of the resultant joints may show the causes of fracture. An experimental design study is conducted, to see how the mechanical performance of such joints could be improved. This method establishes what the best operational limits are and shows how different operational conditions influence the various ways in which fractures occur.