1. W.M. Thomas, E.D. Nicholas, J.C. Needham, M.G. Murch, P. Templesmith, C.J. Dawes, Friction Stir Butt Welding, GB Patent 9125978.8, International Patent PCT/GB92/02203,1991
2. G.K. Padhy, C.S. Wu, S. Gao, J. Mater. Sci. Technol. 34, 1 (2018)
3. C.S. Wu, H. Su, L. Shi, Acta Metall. Sin. 54, 265 (2017). (in Chinese)
4. G. Chen, S. Zhang, Y. Zhu, C. Yang, Q. Shi, Acta Metall. Sin. Engl. Lett. 33, 3 (2020)
5. N. Xu, R.N. Feng, W.F. Guo, Q.N. Song, Y.F. Bao, Acta Metall. Sin. Engl. Lett. 33, 319 (2020)