Region selectivity of nanometer scale crystallization behavior in metallic glass
- 13 Downloads
It has been known that the internal structure of metallic glass is composed of elastic region and fragile region. However, it is not clear whether the distribution of these regions has an effect on the occurrence of crystallization behavior. Here, the molecular dynamics simulation is employed to investigate the nanometer scale crystallization behavior in metallic glass. A regional selective characteristic is revealed for the occurrence of crystallization behavior in the metallic glasses, which is different from that in the melt, showing the unique nature of crystallization behavior in amorphous system. It is observed that the crystallization behavior occurs first in the elastic region dominated by the icosahedral network, rather than in the fragile region dominated by the low-population polyhedron. This phenomenon can be attributed to that the Gibbs free energy barrier between the BCC structure and the low-population polyhedron in the fragile region is higher than the free energy barrier between the BCC structure and the icosahedral network.
The authors are grateful for support from the National Key Research and Development Plan (2016YFB1101003) and the National Natural Science Foundation of China (Grant No. 51271213).
- 7.Huang KQ, Cao CR, Sun YT et al (2016) Direct observation of atomic-level nucleation and growth processes from an ultrathin metallic glass films. J Appl Phys 119:223Google Scholar
- 16.Li W, Bei H, Tong Y et al (2013) Structural heterogeneity induced plasticity in bulk metallic glasses: from well-relaxed fragile glass to metal-like behavior. Appl Phys Lett 103:171910–171910–171910–171915Google Scholar
- 32.Cheng YQ, Ma E (2008) Indicators of internal structural states for metallic glasses: local order, free volume, and configurational potential energy. Appl Phys Lett 93:051910–051910–051910–051913Google Scholar