Outlook
Numerical modeling of friction stir welding

The methods and models available enable us to correctly reproduce the thermal fields and the mixing of welded materials, in order, for example, to optimize the forces brought into play as a function of the operating parameters. With regard to residual effects, microstructure and residual stresses, the challenge here is to go beyond the simple assessment of precipitate dissolution for structurally-hardening alloys, to include phase changes for steels and other materials. The aim is to gain a better understanding of the welded zone as a whole, and to be able to carry out fatigue strength analyses or study any other parameter that is extremely useful for structural design.

Analyzing the welding of dissimilar materials is a much more difficult problem. In fact, it requires us to take into account other physical phenomena, such as the formation of intermetallics, which...