Mechanical Properties of Metallic Glass Alloys

Metallic glass alloys, distinguished by their amorphous atomic arrangements, exhibit exceptional mechanical characteristics including high strength, large elastic limits and remarkable hardness. Unlike crystalline metals, which deform through dislocation motion, these alloys accommodate load by forming narrow shear bands that concentrate plastic strain. Their mechanical performance depends sensitively on composition, processing history and temperature. Tailored quenching rates and thermal treatments can tune the degree of internal disorder, influencing properties such as yield strength and ductility. Advances in understanding vibrational modes and relaxation processes have shed light on mechanisms of energy storage and release, which in turn govern fatigue resistance and fracture behaviour. Owing to their combination of light weight, wear resistance and corrosion tolerance, metallic glass alloys hold promise for applications in biomedical devices, microelectromechanical systems and aerospace components.

Research from Nature Portfolio

Studies of extreme mechanical rejuvenation under compressive loading have demonstrated that bulk metallic glasses can reach high-energy states, reducing hardness by over a third while increasing excess enthalpy to levels equivalent to ultrafast liquid quenching. This work underlines the role of hydrostatic stress in tuning plasticity through controlled energy uptake. Investigations into low-frequency vibrational modes in ultrastable glasses reveal a bifurcation into extended acoustic modes and highly localised soft modes. The latter follow a universal quartic frequency scaling and diminish in number as kinetic stability increases, directly linking microscopic vibrational spectra to macroscopic mechanical robustness. Computational studies of oscillatory shear show that amorphous solids undergo a sharply defined yielding transition independent of preparation history. The character of deformation avalanches shifts qualitatively at a critical strain amplitude, providing a clear benchmark for the onset of irreversible flow.

Mechanical Properties of Metallic Glass Alloys publication trend

The graph below shows the total number of articles in mechanical properties of metallic glass alloys across all publications each year (not limited to Nature Index journals).

Technical terms

Bulk Metallic Glass (BMG): An alloy solidified into an amorphous state, lacking long-range crystalline order.

Shear band: A narrow zone of intense, localised plastic deformation through which an amorphous solid yields.

β-relaxation: Secondary relaxation process involving localised atomic rearrangements below the glass transition temperature.

Rejuvenation: The deliberate increase of configurational energy in a metallic glass to enhance its plasticity.

Boson peak: An excess in the low-frequency vibrational density of states compared with that predicted by Debye theory.

Yield transition: The critical point at which an amorphous material shifts from elastic to irreversible plastic deformation under stress.

References

1. Extreme rejuvenation and softening in a bulk metallic glass. Nature Communications (2018).
2. Low-frequency vibrational modes of stable glasses. Nature Communications (2019).
3. The yielding transition in amorphous solids under oscillatory shear deformation. Nature Communications (2017).
4. Stored energy in metallic glasses due to strains within the elastic limit. The Philosophical Magazine A Journal of Theoretical Experimental and Applied Physics (2016).
5. Controlled Rejuvenation of Amorphous Metals with Thermal Processing. Scientific Reports (2015).
6. The β-relaxation in metallic glasses. National Science Review (2014).