High-Strength β-Phase Magnesium–Lithium Alloy Prepared by Multidirectional Rolling

Abstract

Magnesium–lithium alloys are popular in the lightweight application industry for their very low density. However, as the lithium content increases, the strength of the alloy is sacrificed. Improving the strength of β-phase Mg–Li alloys is urgently needed. The as-rolled Mg-16Li-4Zn-1Er alloy was multidirectionally rolled at various temperatures in comparison to conventional rolling. The results of the finite element simulations showed that multidirectional rolling, as opposed to conventional rolling, resulted in the alloy effectively absorbing the input stress, leading to reasonable management of stress distribution and metal flow. As a result, the alloy’s mechanical qualities were improved. By modifying the dynamic recrystallization and dislocation movement, both high-temperature (200 °C) and low-temperature (−196 °C) rolling greatly increased the strength of the alloy. During the multidirectional rolling process at −196 °C, a large number of nanograins with a diameter of 56 nm were produced and a strength of 331 MPa was obtained.

Keywords

• bcc Mg–Li alloy
• multidirectional rolling
• rolling temperature
• nanograins
• dislocation