Study on Heat Treatment of Aerospace Aluminum Alloy Welded FSW

Abstract

The precisely controlled heat treatment was researched to meet the special requirements of the aerospace industry on materials. 2219 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties were investigated correspondingly. The causes of the weakened joint strength in friction stir welding were analyzed and summarized. The tensile properties show that the average tensile strength of the samples was increased to 393MPa and the elongation was increased to 12.6% of the base metal. Through the special recrystallization technology with high temperature oscillating heat treatment to hold the fine grain at short time, the ductility can be restored and softening can be eliminated, which will improve the performance in mechanical intensity of aerospace aluminum alloy.