Substantially enhanced plasticity of bulk metallic glasses by densifying local atomic packing

Abstract

Introducing regions of looser atomic packing in bulk metallic glasses (BMGs) was reported to facilitate plastic deformation, rendering BMGs more ductile at room temperature. Here, we present a different alloy design approach, namely, doping the nonmetallic elements to form densely packed motifs. The enhanced structural fluctuations in Ti-, Zr- and Cu-based BMG systems leads to improved strength and renders these solutes’ atomic neighborhoods more prone to plastic deformation at an increased critical stress. As a result, we simultaneously increased the compressive plasticity (from ∼8% to unfractured), strength (from ∼1725 to 1925 MPa) and toughness (from 87 ± 10 to 165 ± 15 MPa√m), as exemplarily demonstrated for the Zr20Cu20Hf20Ti20Ni20 BMG. Our study advances the understanding of the atomic-scale origin of structure-property relationships in amorphous solids and provides a new strategy for ductilizing BMG without sacrificing strength.

Lattice distortion and re-distortion affecting irradiation tolerance in high entropy alloys

“…In furtherance of the preceding arguments and based on the premise that there exists a correspondence between the potential energy of a system and microstructural stability, the energetics evolution at the atomic scale can reference the structural stability or tolerance of alloys to stress application, irradiation, etc. , 49 and for this reason, there is a strong requirement to analyze the energetic landscapes of the four models under irradiation. With reference to this, the potential energy distributions of atoms in the models are presented in Fig.…”

Quenched-in liquid in glass

“…This quenched-in dynamic 'microstructure' also helps us unravel the structure-property relations of metallic glasses [40]. It is well known that being out-of-equilibrium, metallic glasses undergo thermal evolution below T g like all other glasses.…”

Fatigue responses of metallic glass‐based stochastic network nanomaterial: Superior strain‐hardening ability

“…MGs lack crystallographic defects such as dislocations, twinning, and stacking fault due to their disordered structures, [1][2][3] exhibiting unique mechanical properties, such as high elastic limit, good corrosion resistance, and high strength. [4][5][6] However, the fatigue resistance of MGs is poor, which severely hampers their multifunctional applications. [7][8][9] Upon alternating cyclic loading, MGs fracture even in low-stress conditions, resulting in low fatigue limits.…”