Improvement of Room Temperature Formability in Mg-Zn-Zr Alloy Sheet by Thermo-Mechanical Treatment

초록

Magnesium alloy sheets generally show a strong basal texture, resulting in a poor formability due to their hexagonal closed-packed crystal structure having an axial ratio of 1.624, which is closed to the ideal value of 1.633. Lots of attempts have been made in order to improve the formability of Mg alloy sheets by the addition of alloying elements (Ca/RE with Zn) or applying severe plastic deformation (ECAP, HPT, etc.). In this study, the texture evolution of Mg-Zn-Zr and Mg-Zn-Zr-Gd alloys during the thermo-mechanical treatment have been analyzed and compared in detail. The modified thermo-mechanical treatment was subjected to achieve similar microstructure and texture evolution in both alloys, resulting in a weakened texture and a comparable formability in Mg-Zn-Zr alloy to Mg-Zn-Zr-Gd alloy at room temperature. This study suggests that the formability of Mg alloys exhibiting a strong basal texture also can be significantly improved by thermo-mechanical treatment.

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