Microstructure and Properties of Welded Joint of 6061-T6 Aluminum Alloy Obtained by Friction Stir Welding
6061-T6 aluminum alloy plate with 6 mm thickness was welded by friction stir welding,and the microstructure and properties of the welded joints were studied.The results show when the rotation speed of stir-pin is lower,the welded joints generates obvious spiral fracture which is unique for friction stir welding,and the property of the joint is poor.The property of the joint improves when the speed of stir-pin increases.X-ray diffraction analysis show that some strengthening phase is re-dissolved due to higher temperature of welding area.The reinforcing phase in weld seam is still β " phase.