Resumen de Dissimilar autogenous disk-laser welding of Haynes 188 and Inconel 718 superalloys for aerospace applications.
Fabrizia Caiazzo, Vittorio Alfieri
New materials and new processing methods are being progressively tested for aerospace applications in order to meet the challenges of innovation and operating cost reduction, but extensive studies are needed before any change may be introduced in industrial environments. Laser beam welding is considered to be a valid alternative to arc and electron beam welding for aerospace applications; in particular, interest is growing toward disk-laser sources due to their increased beam quality. The autogenous disk-laser welding of Haynes 188 and Inconel 718, which are among the most common and representative aerospace superalloys, is discussed in the paper. The aim is to provide a comprehensive description of the quality issues in terms of both structure and shape defects, via non-destructive tests and dimensional checks referring to special needs as required in industrial specifications. A systematic approach is adopted, defining both the main governing parameters and the crucial response variables at a pre-design stage, and a three-factor experimental plan with power, welding speed, and beam angle is arranged to feed the optimization process. The suggested optimal welding conditions are assessed in terms of the resulting Vickers micro-hardness and tensile strength, and convincing results are achieved.
