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Twin roll casting (TRC), with a relatively fast solidification rate, is an excellent production method with promising potential for producing wrought semi or final Mg alloy products that can often suffer from poor formability. We investigate in this study the effect of the TRC method and the subsequent heat treatment on the microstructure and deformation mechanisms in Mg-Zn-Zr-Nd alloy deformed at room temperature using the in-situ neutron diffraction and acoustic emission techniques and ex-situ texture measurement and microscopy, respectively. Although a higher work hardening is observed in the rolling direction due to the more intensive -type dislocation activity, the difference in the mechanical properties of the specimens deformed in the RD and TD directions is small in the as-rolled condition. An additional heat treatment results in recrystallization and significant anisotropy in the deformation. Due to the easier activation of the extension twinning in the TD given by texture, the yield stress in the TD is approximately 40% lower than that in the RD. [ABSTRACT FROM AUTHOR]

Pre‐straining of magnesium alloy modifies the final texture of the material and therefore leads to a different deformation behavior during subsequent loading. At the same time, heat treatment in the context of thermo‐mechanical procedures is used as softening mechanism, as well as for age hardening processing. In mechanical conditions with twin‐dominated deformation in textured magnesium alloys, the twin boundaries can be pinned if existing after a pre‐deformation of samples and therefore influence their mobility. The impact of the ongoing mechanical behavior is discussed. In the present paper, a procedure of pre‐compression and reverse tensile loading of extruded binary magnesium alloy Mg–1 wt% Zn (Z1) is used and intermediate aging at 200 °C is applied in two different routes. The effect of the heat treatment on the flow behavior during subsequent mechanical loading is correlated with the dominating deformation mechanisms revealed by in situ acoustic emission measurements and ex situ scanning electron microscopy. The pinning of twin boundaries can restrict their mobility in experimental environments that favor the recovery of the samples. As a result, new twins easily nucleate if the concurrent re‐orientation of the lattice is favorable for strain accommodation. The effect of pre‐compression and concurrent activation of slip and twinning as well as intermediate isothermal aging on the mechanical response during subsequent tensile loading is elucidated by acoustic emission technique. Detwinning can proceed by migration of pinned twin boundary and by activation of new twins inside existing twin lamellae. [ABSTRACT FROM AUTHOR]

The influence of isothermal aging, i.e. solute segregation and precipitation, on the mobility of {10−12} twin boundaries during mechanical loading of a binary Mg-1wt.%Zn alloy was investigated. Segregation along twin boundaries leads to a pinning effect and therefore, twin growth and shrinkage based on twin boundary migration are restricted. The development of microstructure changes, especially the twinning activity, is tracked by using scanning electron microscopy. During reverse loading, a reduction of the twinned volume fraction (detwinning) is realized either by (i) nucleation of new twins inside already existing twin lamellae or by (ii) migration of pinned twin boundaries, similarly to the case, when no heat treatment is applied. No effect of the orientation of the grain with respect to the loading direction during detwinning was observed. [ABSTRACT FROM AUTHOR]