Cavity Nucleation Study during Quasi-Superplasticity of an Ultralight Coarse-Grained Rolled Mg-7.28Li-2.19Al-0.1Y Alloy

Cao Furong,Zhou Bijin,Guo Nanpan,Liang Jinrui

doi:10.35840/2631-5076/9271

Abstract

Cavity or cavitation is a phenomenon in superplasticity and creep and is significant to the prediction of cavity mechanism. However, compared to cavity growth, cavity nucleation is rarely reported in magnesium alloy, especially Mg-Li alloy. To investigate the cavitation nucleation, a novel Mg-7.28Li-2.19Al-0.1Y alloy has been fabricated by hot rolling and cold rolling; its flow stress and microstructural cavitation at elevated temperatures were investigated by optical microscopy and tensile tester.

Highlights

Magnesium-lithium (Mg-Li) alloy is the lightest nonpoisonous alloy
Our investigation contents include three aspects: (i) A novel Mg-7.28Li-2.19Al-0.1Y alloy has been fabricated by hot rolling and cold rolling; (ii) Its flow stress and microstructural cavitation at elevated temperatures were investigated; (iii) The free energy map was plotted to analyze the cavitation nucleation mechanism and corroborated in this alloy
For different flow stress curves, the flow stress level decreases with increasing temperature and/or decreasing strain rate

Summary

Introduction

Due to extremely low density, excellent specific stiffness, good weight-to-density ratio, good electromagnetic shielding property, and damping property, studies on Mg-Li alloys have attracted extensive attention from the researchers, for room temperature property and microstructure [1-3] and for high temperature behavior, in particular, superplasticity [4-9]. Under this background, we designed and fabricated a novel two-phase Mg-7Li-2Al-1Y alloy and investigated its high temperature behavior. Our investigation contents include three aspects: (i) A novel Mg-7.28Li-2.19Al-0.1Y alloy has been fabricated by hot rolling and cold rolling; (ii) Its flow stress and microstructural cavitation at elevated temperatures were investigated; (iii) The free energy map was plotted to analyze the cavitation nucleation mechanism and corroborated in this alloy

Experimental Procedures

Results and Discussion

Conclusions