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A combination of conventional calorimetry, ultra-fast scanning calorimetry and resistive heating gives access to heating rates exceeding 6 orders of magnitude allowing to probe crystallization kinetics and mechanisms in a Cu-Zr-Al metallic glass. Continuous-heating-transformation and double-peak time-temperature-transformation diagrams are constructed and related to the formation of glass–crystal composites with enhanced ductility. The metastable B2-CuZr phase becomes dominantly formed at a heating rate of ~102 K s−1 and higher. A critical heating rate to bypass crystallization is ~10,000 K s−1. For isothermal annealing at >850 K, only one crystallization event is detected; for lower temperatures, a complex two-step transformation occurs. Image, graphical abstract [ABSTRACT FROM AUTHOR]

A density variation in shear bands visible by electron microscopy is correlated with compositionally altered locations measured by atom-probe tomography in plastically-deformed Al 85.6 Y 7.5 Fe 5.8 metallic-glass ribbons. Two compositionally distinct regions are identified along shear bands, one is Al-rich (~92 at.%), the other is Al-depleted (~82.5 at.%) and both regions show marginal concentration fluctuations of Y and Fe. The elemental re-distribution is observed within shear bands only, and no chemical exchange with the surrounding glassy matrix is observed. Unlabelled Image [ABSTRACT FROM AUTHOR]

Image, graphical abstract The relationship between remelting and undercooling in Co 38.2 Si 61.8 (at. %) eutectic alloys is investigated with in situ X-ray diffraction experiments and microstructural observations. High-energy in situ X-ray diffraction during uncoupled eutectic solidification of undercooled Co 38.2 Si 61.8 allows the phase fractions to be tracked through time and reveals remelting of primary solid coincident with the formation of secondary solid. Microstructure analysis suggests that remelting occurs at the supersaturated dendrite interior. The remelted solid fraction is quantified for a wide range of solidification conditions and found to be strongly correlated with the secondary undercooling of the melt, yet independent of convection and containerless processing technique. A remelting limit was observed in experiments with primary CoSi 2 , indicating that system-specific factors impose additional constraints. [ABSTRACT FROM AUTHOR]