Formation of α’ titanium welds by friction stir welding

Abstract

Abstract In the present study, investigation of the macrostructure of α’ titanium alloy weld produced by the friction stir welding has been carried out. The welding process modes were also selected. It is shown that in case of insufficient load on the tool, an open weld defect is formed. Increasing the load (with decreasing RPM) eliminates the open tunnel and minimizes defects. Despite the presence of defects, the strength of welds has reached the strength of the initial material. As a result of FSW, grain size has been reduced by 7.3 times, but the load increase has not affected the grain structure. The results of the research show that the part of welding tool had been stirred in the structure of weld. However, nickel base alloy tool had passed about 500 mm of weld, before starting to wear out.