Effect of second-phase particle evolution in a twin-roll-casted Al-Mg-Si alloy on recrystallization texture and mechanical anisotropy

Abstract

In this study, the evolution of second-phase particles in a twin-roll-casted (TRC) Al-Mg-Si alloy is analyzed, and the influence of this evolution on recrystallization texture and mechanical anisotropy is investigated. Based on the obtained results, homogenization significantly affects second-phase particles by promoting dissolution of Mg2Si phases, transformation of the Fe-rich intermetallic phase, and precipitation of AlMgSi dispersoids. During TRC and homogenization, different distributions of second-phase particles (coarse intermetallic phases and fine dispersoids) are achieved. These distributions control the recrystallization texture intensity and components and have a great impact on mechanical anisotropy. For example, the TRC sheet that has a large number of coarse intermetallic particles is characterized by very weak Cube-ND {001} 〈310〉 texture. This sheet has the highest average normal anisotropy r (0.71) and lowest planar anisotropy ∆r (0.077) among the investigated samples. Compared to the non-homogenized sheet, the homogenized counterparts exhibit enhanced texture intensity due to the dissolution or transformation of the intermetallic phase and increase in the number of fine dispersoids. Moreover, the main texture component in these sheets gradually changes to Cube {001} 〈100〉 orientation. To improve the application prospects of the TRC Al-Mg-Si alloy, further studies must be conducted regarding the effects of alloy designing and short process optimization on the material.