We report a universal scaling law, tau_{y} = 3R(T_{g}-RT)/V, that uncovers an inherent relationship of the yield strength tau_{y} with the glass transition temperature T_{g} and molar volume V of metallic glasses. This equation is derived from fundamental thermodynamics and validated by various metallic glasses with well-defined yielding. The linearity between tau_{y} and T_{g} demonstrates the...

We report a brittle Mg-based bulk metallic glass which approaches the ideal brittle behavior. However, a dimple structure is observed at the fracture surface by high resolution scanning electron microscopy, indicating some type of "ductile" fracture mechanism in this very brittle glass. We also show, from the available data, a clear correlation between the fracture toughness and plastic process...

To increase the toughness of a metallic glass with the nominal composition Zr57Nb5Al10Cu15.4Ni12.6, it was used as the matrix in particulate composites reinforced with W, WC, Ta, and SiC. The composites were tested in compression and tension experiments. Compressive strain to failure increased by more than 300% compared with the unreinforced Zr57Nb5Al10Cu15.4Ni12.6, and energy to break of the t...

The plastic deformation of Ti45Zr16Be20Cu10Ni9 bulk metallic glass has been investigated by nanoindentation performed with loads ranging from 10 to 200 mN in a wide range of loading rates. The plastic flow in the alloy exhibited conspicuous serrations at low loading rates. The serrations, however, became less prominent as the rate of indentation increased. Atomic force microscopy showed a signi...

Results of calorimetric, differential thermal analysis, and structural measurements are presented for a series of bulk metallic glass forming compositions in the Zr–Ti–Cu–Ni–Be alloy system. The calorimetric data for five alloys, prepared along the tie line between phase separating and nonphase separating compositions, show that the transition from phase separating to nonphase separating behavi...

Metallic glasses have been the subject of intense scientific study since the 1960s, owing to their unique properties such as high strength, large elastic limit, high hardness, and amorphous microstructure. However, bulk metallic glasses have not been used in the high strength structural applications for which they have so much potential, owing to a highly localized failure mechanism that result...

In the field of metallic materials with amorphous structures, it is vitally important to understand the glass formation and to predict glass-forming ability (GFA) in terms of constituent elements and alloy compositions. In this study, an expression has been formulated from first-principles calculations to predict the trend of GFA by hybridizing both internal energies and atomic-scale defect str...

Elastic moduli of the glass and fragility of the corresponding supercooled liquid were found to be correlated in recently published results. In the present work, compositions within the Ca-Mg-Cu system are used to study the relationships between liquid fragility, glass-forming ability and elastic properties. The correlation between liquid fragility and elastic properties already observed for gl...

A high-resolution micro-torsion tester is developed based on electromagnetism, and the shear modulus of metallic glass fiber (Pd40Cu30Ni10P20) is measured using this tester. The torque is measured by a coil-magnet component and the rotation angle is measured by an inductive angular transducer. The calibration results show that the torque capacity of this tester is 1.1 × 10−3 N m with resoluti...

We use coherent x rays to probe the aging dynamics of a metallic glass directly on the atomic level. Contrary to the common assumption of a steady slowing down of the dynamics usually observed in macroscopic studies, we show that the structural relaxation processes underlying aging in this metallic glass are intermittent and highly heterogeneous at the atomic scale. Moreover, physical aging is ...