In this paper. T-joints of Ti-6Al-3Nb-2Zr-1Mo titanium alloy were joined with friction stir welding. and microstructure evolution and forming mechanism were studied. The effect of using tungsten inert gas welding to heat additionally the FSW was investigated. https://www.roneverhart.com/Hosa-SH-8X4-25-Stage-Box-Non-locking-8x4-25-p37478/