Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening.

ABSTRACT: Several recent papers report spectacular, and unexpected, order of magnitude improvement in creep life of alloys upon adding small amounts of elements like zinc. This microalloying effect raises fundamental questions regarding creep deformation mechanisms. Here, using atomic-scale characterization and first principles calculations, we attribute the 600% increase in creep life in a prototypical Mg-rare earth (RE)-Zn alloy to multiple mechanisms caused by RE-Zn bonding-stabilization of a large volume fraction of strengthening precipitates on slip planes, increase in vacancy diffusion barrier, reduction in activated cross-slip, and enhancement of covalent character and bond strength around Zn solutes along the c-axis of Mg. We report that increased vacancy diffusion barrier, which correlates

SUBMITTER: Choudhuri D 

PROVIDER: S-EPMC5722870 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature