It is known that the glass forming-ability (GFA) of bulk metallic glasses (BMGs) can be greatly enhanced via minor element additions. However, direct evidence has been lacking to reveal its structural origin despite different theories hitherto proposed. Through the high-resolution transmission-electron-microscopy (HRTEM) analysis, here we show that the content of local crystal-like orders increases significantly in a Cu-Zr-Al BMG after a 2-at% Y addition. Contrasting the previous studies, our current results indicate that the formation of crystal-like order at the atomic scale plays an important role in enhancing the GFA of the Cu-Zr-Al base BMG.

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.

Grain refinement can drastically increase the strength of metals. However, this approach tends to become less effective or even inverses once grain sizes are reduced to very small scales, generally below 10 ~ 20 nanometers. This softening effect emerges from grain boundary instability and the limited ability of dislocations to form and move within such nanosized grains. However, grain boundary stability can be tuned by solute decoration or grain boundary relaxation. In this context, we present a strategy to achieve superior strength and plasticity in nanograined metals simultaneously. The formation of oxygen (O)-rich clusters at grain boundaries can significantly improve grain boundary stability, even at the 3 nm grain size model (CoCrNi) ₈₇ O ₁₃ (at.%) alloy investigated in this study. Furthermore, the presence of O-rich clusters in grain interiors promotes the accumulation and multiplication of dislocations, which facilitates strain hardening during deformation. Consequently, despite being situated in the inverse Hall-Petch regime, this (CoCrNi) ₈₇ O ₁₃ alloy exhibits a remarkable yield strength of ~3.6 GPa and retains a uniform plastic strain of over 50% under micropillar compression. These findings therefore provide a universal design strategy for nanograined metals aimed at utilizing O clusters to achieve the highly desired combination of high strength and large deformability.

Superelasticity – exhibiting either Hookean (linear) or non-Hookean (nonlinear) recoverable strain beyond 2% – has been realized in distinct material systems such as metallic glasses, shape memory alloys, strain glass alloys and Gum metals, enabling diverse technological applications. Here we demonstrate that, through compositional tuning in a high-entropy alloy, the elastic behavior can be continuously and reversibly modulated between Hookean superelasticity, non-Hookean superelasticity with an ultrahigh recoverable strain of ~8%, and back to the Hookean regime. By combining atomic-scale strain mapping and extensive first-principles calculations, we reveal that this tunability is governed by a hidden strain order, arising from frustrated crystallization of two competing phases. As a result, local lattice distortion arises, producing a heterogeneous strain landscape that modulates phase stability, phase transformation propensity, and elastic response. Our findings establish a materials design strategy for programming Hookean and non-Hookean elasticity behavior on demand, with promising applications in microelectromechanical systems, high-precision actuators, and adaptive damping devices.

The structure of Cu₅₀Zr₅₀ and Co₅₆Ta₃₅B₉ metallic glass thin films (MGTF) was effectively tailored via various applied substrate temperatures by means of the magnetron sputtering technology. Obviously enhanced hardness and elastic modulus are achieved by different compositional MGTFs by increasing the substrate temperature. Compared with the CuZr MGTFs, the CoTaB MGTF deposited at 473 K displays the smaller strain-rate sensitivity exponent, m, and a weaker spectrum intensity based on the nanoindentation creep test, suggesting its better creep resistance. In addition, the STZ volume of the CoTaB MGTF significantly decreases after depositing at higher temperature. According to the nano-scratch analysis, the CoTaB MGTF at the substrate temperatures of 473 K performs the shallower scratch width and the larger H³/E² value, indicating its better tribological property.