Research Progresses on Thermal Stabilization of Metal Nanocrystalline Alloys

In nano-structured metals, due to grain size decreasing, grain boundary volume fraction increases markedly, which leads to a high driving force for grain growth. So nanocrystalline metals are always remaining at an unstable state upon heating, or even at room temperature, resulting in obstacles in the aspects of their fabrication and application. In this paper, the research progresses on thermal stability of binary nanocrystalline alloys at present stage are introduced from the view of thermodynamics and kinetics. Main theoretical models such as Trelewicz/Schuh (TS) model, Wynblatt/Ku (WK) model, and strategy adopted by Koch et al in thermodynamics stabilization, and basic theory in kinetics stabilization are reviewed and compared.