Latent Hardening in Pure Magnesium Single Crystals

Abstract

<p>In order to better understand work hardening behavior of pure magnesium, latent hardening experiments with magnesium single crystals were carried out. Large magnesium single crystal samples were first deformed in tension, and subsequently sectioned for secondary tension tests. Three different initial crystallographic orientations of magnesium single crystals were prepared: crystals A and B were oriented for basal <a> slip, while crystal C was oriented for {1 012} twinning. The latent hardening test from type A and B crystals revealed that the LHR in coplanar system arising from basal - basal dislocations interactions was close to unity, whereas the LHR in non-coplanar system arising from basal - 2nd order pyramidal dislocation interactions was around 15. The interactions between {1012} twins and various slip dislocations were investigated using type C crystals. It was found that the {10 12} twins contributed to large strain hardening from at least a dynamic Hall - Petch mechanism. However, the role of {10 12} twins is complicated and further studies to understand the hardening mechanism due to {10 12} twinning are necessary.</p>