Review on Quantum Mechanically Guided Design of Ultra-Strong Metallic Glasses

Abstract

Quantum mechanically guided materials design has been used to predict the mechanical property trends in crystalline materials. Thereby, the identification of composition-structure-property relationships is enabled. However, quantum mechanics based design guidelines and material selection criteria for ultra-strong metallic glasses have been lacking. Hence, based on an ab initio model for metallic glasses in conjunction with an experimental high-throughput methodology geared toward revealing the relationship between chemistry, topology and mechanical properties, we propose principles for the design of tough as well as stiff metallic glasses. The main design notion is that a low fraction of hybridized bonds compared to the overall bonding in a metallic glass can be used as a criterion for the identification of damage-tolerant metallic glass systems. To enhance the stiffness of metallic glasses, the bond energy density must be increased as the bond energy density is the origin of stiffness in metallic glasses. The thermal expansion, which is an important glass-forming identifier, can be predicted based on the Debye-Grüneisen model.

Fracture and fatigue behaviour of a laser additive manufactured Zr-based bulk metallic glass

“…The present results in Fig. 12 indicate that the oxygen may have an affinity for Zr and stretch the Zr-Zr pairs, which in turn may induce increased bond hybridization which is thought to negatively affect fracture toughness [59]. To test such a hypothesis, future work might focus on using ab initio calculations to examine the role of oxygen in affecting the electronic structure of Zrbased metallic glasses.…”

High strain rate in situ micropillar compression of a Zr-based metallic glass

“…It should also be noted that oxide nanocrystals are not expected to be present based on our previous TEM investigations [28]. Rather, the inclusion of oxygen is thought to cause an increased level of directional bonding in the structural ordering, as suggested in Reference [26].…”

“…2 show that changes are observed in the local ordering as the oxygen concentration is increased and suggest that the oxygen may have an affinity for Zr and stretch the Zr-Zr atomic pairs. Oxygen atoms situated between Zr-Zr pairs may also induce increased bond hybridisation which is thought to negatively affect fracture toughness of BMGs [26]. Moreover, the reduction of 'BMG-like' mechanical behaviour is supported by the DSC results of Fig.…”

“…Variations in the local clustering of atoms lead to changes in shear band dynamics and density [22]; local soft spots and/or high medium range order in the structure act as sites with a high propensity for shear transformation zone (STZ) activation [20,23], with clear consequences on the transition to plastic flow during material deformation [24]. Changing the local chemical structure can also affect the response at high strain rates, as demonstrated by Inoue and co-workers for Zr-Cu-Al amorphous alloys with various amounts of Ni additions via Charpy impact testing [25], while the degree of hybridised bonding has also been shown to be linked to the fracture toughness of metallic glasses [26]. From instrumented nanoindentation experiments, Schuh and Nieh demonstrated that the composition of the glass alloy had a significant effect on the serrated flow behaviour and sensitivity to strain-rate effects, further supporting the importance of local atomic arrangements on the mechanical response [27].…”

Opportunities of combinatorial thin film materials design for the sustainable development of magnesium-based alloys

“…The combinatorial approach has been e.g. successfully applied to the design of ultra-strong metallic glasses or low-cost alternatives to nickel-base superalloys for medium-to-high temperature structural applications 16 , 17 .…”