Eliminating root defect in Al/Ti dissimilar friction stir welded via the double-side process

Abstract

The root defect is easy to occur in the conventional friction stir welded (C-FSW) Ti/Al dissimilar joints because of the thermophysical properties of titanium alloy. Double-side friction stir welding (DS-FSW) may be a solution to eliminate root defects. This work performed microstructure analyses of the Al/Ti interface for both C-FSW and DS-FSW joints and comprehensively investigated the effects of root defects. The results show that the mechanical properties of the Al/Ti C-FSW joints are severely weakened by root defects. Tensile strength of the DS-FSW joints was 310.8 MPa, which is 73 MPa high than the C-FSW joints. The DS-FSW process can effectively remove the root defects which offers a novel approach to achieve high-quality joining of Al/Ti dissimilar structures.

KEYWORDS:

• Al/Ti dissimilar joints
• double-side friction stir welding
• root defect
• mechanical property
• lack of root penetration defect
• kissing bond

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the National Natural Science Foundation of China (Grant Nos. 52275349 and 52035005), the Key Research and Development Program of Shandong Province (grant number 2021ZLGX01) and the Qilu Young Scholar Program of Shandong University.