S.J. Horstemeyer

Time Dependent Springback of a Magnesium Alloy

Abstract A time dependent springback was observed in a Mg–Al–Zn (AZ31) rolled sheet after three-point bending at room temperature (RT). Two types of test were performed: (1) baseline springback – specimens were bent and immediately released and the springback was measured every month; (2) springback after holding – after bending, specimens were held in the bent state for up to five months, and the springback was measured after release. It was found that the springback increased nonlinearly with time in all the specimens. The springback dramatically decreased after being held for one month compared with specimens that were not held. The decline in springback increased as the holding time increased. These results indicate that creep and creep recovery occurred. Microstructure examinations revealed high density { 1 0 1 ‾ 2 } 〈 1 0 1 ‾ 1 ‾ 〉 twins in the compression zone of the bent specimens in the form of localized twin bands. After the specimens were unloaded, detwinning occurred and continued spontaneously over the five month time period, contributing to the observed time dependent springback.

Anomalous Strain Rate Sensitivity of \( \{ 10\overline{1}2\} \) \( \langle 10\overline{1}\overline{1}\rangle \) Twinning in a Magnesium Alloy at High Temperature

Anomalous strain rate sensitivity of {101¯2}\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}

Experimental Study of High Velocity Penetration of an Aluminum Target Plate by a Spherical Projectile

\{ 10\overline{1} 2\}

Inverse strain rate sensitivity of bendability of an AZ31 sheet in three-point bending

\end{document}〈101¯1¯〉\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}

Anomalous Twin Bands in AZ31 Magnesium Sheet Bending

\langle 10\overline{1}\overline{1}\rangle

Localized twin bands in sheet bending of a magnesium alloy

\end{document} twinning was observed in a Mg-Al-Mn magnesium alloy during extrusion around 723 K (450 °C). The density of {101¯2}\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}