Progress in research of tool materials for friction stir welding of high-strength metals

Friction stir welding technology overcomes the weaknesses of traditional welding technology,especially in the welding of soft materials such as magnesium and aluminum. But the application of friction stir welding to high-strength metals such as titanium and steel,is still limited by the tool materials. It has become the focus of researchers all over the world to choose a suitable material and develop a cheap and reliable stir tool. In this paper,the application of tool materials to the welding of high-strength metals at home and abroad was described,and the performance,advantages and disadvantages of each material were analyzed. Meanwhile,the application development of tools was prospected.