Ni-P nanoglass prepared by multi-phase pulsed electrodeposition

<p>Ni-P nanoglass consisting of nanometer-sized amorphous grains separated by amorphous interfaces was prepared by a specially designed multi-phase pulsed electrodeposition technique. The microstructure of the deposited Ni-P nanoglass was confirmed by X-ray diffraction, high-resolution transmission electron microscopy, small-angle X-ray scattering, and X-ray photoelectron spectroscopy. The formation of the Ni-P nanoglass, which is characterized by inhomogeneities on the nanometer length scale, is achieved via proper control of the rate of cluster formation and cluster growth by a multi-phase pulsed electrodeposition process.</p

Correlations of multiscale structural evolution and homogeneous flows in metallic glass ribbons

Studying the flow behavior is critical to understand the deformation mechanism of amorphous solids. However, detecting the basic flow events in amorphous solids is challenging. Here, by simultaneous SAXS/WAXS, elementary flow carriers in wound metallic glasses are identified from flow-induced structural heterogeneities with a radius of gyration of 2.5∼3.5 nm. Their size increases and morphology changes from sphere-like to rod-like under flow. Moreover, the atomic structure exhibits an unusual change to a more disordered state during winding/annealing at the temperature of ∼0.8 Tg. This work provides an atomic-to-nanoscale description of the flow carriers of amorphous solids during deformation. Impact Statement The elementary flow carriers in metallic glasses have a radius of gyration of 2.5∼3.5 nm. During flow, their size increases and morphology changes from sphere-like to rod-like.</p

Enhanced inter-diffusion of immiscible elements Fe/Cu at the interface of FeZr/CuZr amorphous multilayers

<p>Fe₇₅Zr₂₅/Cu₆₄Zr₃₆ amorphous multilayers were prepared by magnetron sputtering. Atom probe tomography was employed to analyze the atomic inter-diffusion at the interface of the multilayers before and after annealing (573 K, 60 min). An unexpected enhanced inter-diffusion of the immiscible elements Fe and Cu was detected at the interface of the multilayers. As the inter-diffusion in amorphous multilayers is much faster than that in the crystalline counterparts, this process may open a way to manipulate or create amorphous multilayers with new properties. This idea agrees with the observation of the variation of magnetic properties of Fe₇₅Zr₂₅/Cu₆₄Zr₃₆ amorphous multilayers.</p> <p><b>IMPACT STATEMENT</b> This paper reveals the enhanced atomic inter-diffusion at the interface of amorphous materials, and may open a way to manipulate or create amorphous multilayers with new properties.</p

Nanoscale Structural Evolution and Anomalous Mechanical Response of Nanoglasses by Cryogenic Thermal Cycling

One of the central themes in the amorphous materials research is to understand the nanoscale structural responses to mechanical and thermal agitations, the decoding of which is expected to provide new insights into the complex amorphous structural-property relationship. For common metallic glasses, their inherent atomic structural inhomogeneities can be rejuvenated and amplified by cryogenic thermal cycling, thus can be decoded from their responses to mechanical and thermal agitations. Here, we reported an anomalous mechanical response of a new kind of metallic glass (nanoglass) with nanoscale interface structures to cryogenic thermal cycling. As compared to those metallic glasses by liquid quenching, the Sc₇₅Fe₂₅ (at. %) nanoglass exhibits a decrease in the Young’s modulus but a significant increase in the yield strength after cryogenic cycling treatments. The abnormal mechanical property change can be attributed to the complex atomic rearrangements at the short- and medium- range orders due to the intrinsic nonuniformity of the nanoglass architecture. The present work gives a new route for designing high-performance metallic glassy materials by manipulating their atomic structures and helps for understanding the complex atomic structure–property relationship in amorphous materials