title: Superior tensile ductility in bulk metallic glass with gradient amorphous structure.
abstract: Over centuries, structural glasses have been deemed as a strong yet inherently 'brittle' material due to their lack of tensile ductility. However, here we report bulk metallic glasses exhibiting both a high strength of ~2 GPa and an unprecedented tensile elongation of 2-4% at room temperature. Our experiments have demonstrated that intense structural evolution can be triggered in theses glasses by the carefully controlled surface mechanical attrition treatment, leading to the formation of gradient amorphous microstructures across the sample thickness. As a result, the engineered amorphous microstructures effectively promote multiple shear banding while delay cavitation in the bulk metallic glass, thus resulting in superior tensile ductility. The outcome of our research uncovers an unusual work-hardening mechanism in monolithic bulk metallic glasses and demonstrates a promising yet low-cost strategy suitable for producing large-sized, ultra-strong and stretchable structural glasses.
authors.affiliation: 1] Laboratory for Microstructures, Institute of Materials Science, Shanghai University, Shanghai 200072, China [2] Centre for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Hong Kong.
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Centre for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Hong Kong.
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong.
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Centre for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Hong Kong.
authors.forename: C T
authors.initials: CT
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hong Kong.
authors.forename: H H
authors.initials: HH
authors.lastname: Ruan
authors.affiliation: Centre for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Hong Kong.
authors.forename: J
authors.initials: J
authors.lastname: Lu
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