Decomposition-induced enhancement of elastic modulus in CuZr metallic glass

Abstract

Metallic glasses usually exhibit lower elastic moduli compared with their crystalline counterparts. Structural relaxation may impel the amorphous structures to lower energy states, which is so far the only way that may moderately elevate the elastic modulus of metallic glasses. In this study, we found that decomposition of a binary CuZr glass may substantially increase its elastic modulus. With intensive plastic straining followed by annealing, the as-quenched homogeneous glass decomposed into two finely spaced (below 10 nm) glassy phases with different chemical compositions. Young’s modulus of the decomposed glass is ∼139% that of the as-quenched one and comparable to the corresponding crystalline phases. The modulus elevation may be attributed to formation of more ordered amorphous phases with a high density of glass/glass interfaces.