摘要

The friction stir welding of AA 3003 aluminum alloy with different initial microstructures was carried out under different welding conditions. The microstructural evolution and mechanical properties of weld joints were investigated. The results showed that the size of recrystallized grains and the amount of second-phase particles in the weld nugget zone (WNZ) decreased with decreasing welding ambient temperature. At the same welding condition, the size of recrystallized grains in the hot bands was smaller than that in the annealed hot bands, while the volume fraction of (Fe,Mn)Al-6 particles in the hot bands was lower than that in the annealed hot bands. The relationship between the yield strength and grain size was characterized by the Hall-Petch equation. The values of sigma(0) and k in WNZ for the hot bands were higher than those for the annealed hot bands.