Recent Patented Hybrid Techniques for Friction Stir Welding of Metallic Materials

Friction stir welding (FSW), invented by The Welding Institute in 1991, has been successfully applied in the aluminum industry. As for the FSW of metallic materials with higher melting point like Cu, Ti, iron and steels, the cost of using durable tools increases remarkably. In this article, an overview of newly patented hybrid welding technique called laser-assisted FSW technique invented by Palm and Frank is given. By means of this new hybrid welding technique the workpiece is preheated before welding, resulting in a significant decrease of applied load and thus the extended life of the tool. In addition to the laser-assisted friction stir welding technique, a variety of other hybrid FSW techniques (e.g., FSW assisted by arc, high frequency induction heating or by electrical heating) are also presented in this article.