Microstructure of Mg–In Alloy Systems and Their Room Temperature Rollability

Abstract

The Mg 0.1 In 0.9 phase with FCC structure was formed in Mg-In and Mg-Al-In alloys. The LCR (Limiting Cold-Rolling ratio) at room temperature tended to increase with increasing area fraction of the Mg 0.1 In 0.9 phase, and the LCR achieved 80% for the single Mg 0.1 In 0.9 phase in both alloys. The hardness value of the Mg 0.1 In 0.9 phase in the Mg-In binary alloys increased after rolling originated from grain-refinement by recrystallization and precipitation hardening due to processing heat generated by rolling at room temperature. On the other hand, the Mg 0.1 In 0.9 phase formed in the Mg-Al-In ternary alloys was stable at room temperature and work hardened after rolling. Since the Mg 0.1 In 0.9 phase dissolves about 5 mol% of Al, substituting Al for In in the Mg-In alloy was effective in reducing density. The density of the Mg 80 Al 7 In 13 (mol%) alloy is 2.60 Mg/m 3 , which is lower than that of Al, and the LCR showed 49%. In Mg-In alloys, the substitution of Al is effective in developing alloys that are easy to process at room temperature and have low density, because the Mg 0.1 In 0.9 phase has a solid solution of Al and contributes to phase stabilization at room temperature.