Reformation Capability of Short-Range Order and Their Medium-Range Connections Regulates Deformability of Bulk Metallic Glasses
Metallic glasses (MGs) typically have high yield strength while low ductility, and the latter is commonly considered as the Achilles' heel of MGs. Elucidate the mechanism for such low ductility becomes the research focus of this field. With molecular level simulations, we show the degree of short-range order (SRO) of atomic structure for brittle Fe-based glass decreases dramatically during the stretch, while mild change occurs in ductile Zr-based glass. The reformation capability for SRO and their medium-range connections is found to be the primary characteristics to differentiate the deformability between the two metallic glasses. We suspect that, in addition to the strength of networks formed by SRO structure, the reformation capability to reform SRO networks also plays the key role in regulating the ductility in metallic glasses. Our study provides important insights into the understanding about the mechanisms accounting for ductility or brittleness of bulk metallic glasses.
The work is supported bythe National Natural Science Foundation of China (NSFC) (Grant No. 11023001, 11425211) and computation is mainly supported by the Supercomputing Center of Chinese Academy of Sciences (SCCAS). We also gratefully acknowledge the helpful discussions with Prof. Huajian Gao and Prof. Evan Ma.
Li, Congling,Wei YJ,Shi XH. Reformation Capability of Short-Range Order and Their Medium-Range Connections Regulates Deformability of Bulk Metallic Glasses[J]. SCIENTIFIC REPORTS,2015,5:12177.