School of Chemistry, The University of Sydney, New South Wales 2006, Australia.
Nat Mater. 2013 Jun;12(6):507-11. doi: 10.1038/nmat3631. Epub 2013 Apr 28.
Our ability to exploit the benefits of metallic glasses depends on identifying alloys of high glass-forming ability (GFA). So far, the established empirical correlations of GFA (ref. ) are statistical guides at best and lack a microscopic rationale. Although simulations have the potential to provide this physical insight into the maximum crystallization rate, crystal nucleation is often too slow to be observed. In contrast, measuring the growth rate of a planar crystal surface represents an accessible route to understanding ordering kinetics. Here we use molecular dynamics simulations to show that the crystal growth rate for an important binary glass former, CuZr, is significantly slower than that of a poor glass former, NiAl. In accounting for this difference, we find that the crystal/liquid interface in NiAl exhibits a significantly greater width than that of CuZr. Our results suggest that the crystal/liquid interfacial structure exerts an important influence on the GFA of alloys.
我们能否充分利用金属玻璃的优势取决于能否识别出具有高玻璃形成能力（GFA）的合金。到目前为止，GFA 的经验相关性（参考文献）最多只是一种统计学指导，缺乏微观理论依据。尽管模拟有潜力为最大结晶速率提供这种物理见解，但晶体成核通常太慢而无法观察到。相比之下，测量平面晶体表面的生长速率是理解有序动力学的可行途径。在这里，我们使用分子动力学模拟表明，对于重要的二元玻璃形成体 CuZr，其晶体生长速率明显慢于较差的玻璃形成体 NiAl。在解释这种差异时，我们发现 NiAl 中的晶体/液体界面比 CuZr 的界面宽得多。我们的结果表明，晶体/液体界面结构对合金的 GFA 有重要影响。
