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    Correlation between atomic structure evolution and strength in a bulk metallic glass at cryogenic temperature
    (London : Nature Publishing Group, 2014) Tan, J.; Wang, G.; Liu, Z.Y.; Bednarčík, J.; Gao, Y.L.; Zhai, Q.J.; Mattern, N.; Eckert, J.
    A model Zr41.25Ti13.75Ni10Cu12.5Be22.5 (at.%) bulk metallic glass (BMG) is selected to explore the structural evolution on the atomic scale with decreasing temperature down to cryogenic level using high energy X-ray synchrotron radiation. We discover a close correlation between the atomic structure evolution and the strength of the BMG and find out that the activation energy increment of the concordantly atomic shifting at lower temperature is the main factor influencing the strength. Our results might provide a fundamental understanding of the atomic-scale structure evolution and may bridge the gap between the atomic-scale physics and the macro-scale fracture strength for BMGs.
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    Ductile bulk metallic glass by controlling structural heterogeneities
    (London : Nature Publishing Group, 2018) Scudino, S.; Bian, J.J.; Shakur Shahabi, H.; Şopu, D.; Sort, J.; Eckert, J.; Liu, G.
    A prerequisite to utilize the full potential of structural heterogeneities for improving the room-temperature plastic deformation of bulk metallic glasses (BMGs) is to understand their interaction with the mechanism of shear band formation and propagation. This task requires the ability to artificially create heterogeneous microstructures with controlled morphology and orientation. Here, we analyze the effect of the designed heterogeneities generated by imprinting on the tensile mechanical behavior of the Zr52.5Ti5Cu18Ni14.5Al10 BMG by using experimental and computational methods. The imprinted material is elastically heterogeneous and displays anisotropic mechanical properties: strength and ductility increase with increasing the loading angle between imprints and tensile direction. This behavior occurs through shear band branching and their progressive rotation. Molecular dynamics and finite element simulations indicate that shear band branching and rotation originates at the interface between the heterogeneities, where the characteristic atomistic mechanism responsible for shear banding in a homogeneous glass is perturbed.