Influence of different solution methods on microstructure, precipitation behavior and mechanical properties of Al-Mg-Si alloy

The effects of different solution methods on microstructure, mechanical properties and precipitation behavior of Al-Mg-Si alloy were investigated by scanning electron microscope, transmission electron microscope, tensile test, and differential scanning calorimetry. The results revealed that the recrystallized grains of the alloy after the solution treatment with hot air became smaller and more uniform, compared with solution treatment with electrical resistance. The texture of the alloy after two solution treatment methods was different. More rotated cube components were formed through solution treatment with electrical resistance, which was better for improving the drawability of the alloy. The strength of the alloy under the solution treatment with hot air was higher before stamping, because of the small uniform grains and many clusters in the matrix. The alloy solution treated with hot air also possessed good bake hardenability, because the transformation occurred on more clusters in the matrix.

Texture evolution and mechanical properties of Al-Mg-Si alloys at different intermediate annealing temperatures

Intermediate annealing treatment produces different effects on the state of particles in Al-Mg-Si alloy sheets,thereby affecting their recrystallization textures and formability.To improve the formability of the sheets,the effects of different intermediate annealing temperatures on the texture evolution and mechanical properties of these sheets for automotive applications were studied using optical microscope(OM),scanning electron microscope(SEM) and tensile tests.The results reveal that intermediate annealing temperature has a significant influence on the recrystallization textures and average plastic strain ratio(r).After solution treatment,all the alloy sheets possess similar recrystallization texture components comprising of cubeND {100}<310> and P {011}<122> orientations,whereas a characteristic strong cube-oriented {100} <001>texture is observed only in the alloy annealed at a temperature of 380℃.However,in comparison with the alloy not annealed,and the alloy annealed at 550℃,the alloy annealed at 380℃ possesses a lower average r value.Furthermore,the relationship between textures and r value was analyzed by using the Taylor full constraints model in this study.