Study on properties of aluminum alloy welded by friction stir welding

Abstract

In order to meet the special requirements of aerospace industry for materials of aluminum alloy, the precisely controlled heat treatment was studied. The 2219 aluminum alloy welded plate was prepared by friction stir welding, and its microstructure and mechanical properties were studied correspondingly. The reasons for strength reduction of welded joints are analyzed and summarized. The research results showed that the average tensile strength of the welded joints increased to 393 Mpa and the elongation increased to 12.6% of the base metal. With the special recrystallization technology of high temperature oscillation heat treatment, the fine grains can be maintained, the plasticity of aluminum alloy can be restored, which means that the softening problem can be eliminated and the mechanical strength can be improved.