The effect of strain-induced melt activation process on the microstructure and mechanical properties of Ti-refined A6070 Al alloy

Abstract

In current research, the effect of Ti (Al–5Ti–1B) master alloy on the macrostructure of A6070 Al alloy has been investigated. The results revealed that the optimum Ti content to achieve a fine-grained structure was found to be 0.02wt.%. Then, in order to investigate the effect of strain-induced melt activation (SIMA) process on the microstructures of unrefined and 0.02% Ti-refined A6070 alloy optical and scanning electron microscopy (SEM) were used. The results showed that as the applied pre-deformation increases, the globular size decreases and the sphericity of globules increases. The results revealed that for the desired microstructure of the alloy during SIMA process, the optimum temperature, holding time and strain are 630°C, 20min and 30%, respectively. The results showed that the average globule size achieved to a minimum value of 68μm and 55μm in the unrefined and 0.02% Ti-refined alloy, respectively. The results obtained from tensile testing showed that SIMA process increases the tensile properties of the alloy significantly, although due to occurrence of recrystallization during SIMA process, tensile ductility increases more than tensile strength.