Strength at the nanoscale: fundamental mechanisms of plasticity in nano-structured materials

金属合金在很大程度上由于其高强度而在工程应用中有用。最近，材料科学家发现，这种强度因所谓的“纳米结构材料”而进一步增强。它们通常是与传统金属相同的合金，但具有细化到纳米级的特殊微结构特征。然而，人们发现，控制强度和延展性的主要机制在纳米结构材料中与传统材料不同。这种新的物理学并没有被很好地理解，但它发生在现代原子模拟和纳米实验都能达到的长度尺度上。这是一种独特的制度，在这种制度下，模拟和实验之间的直接联系是可能的。

Metallic alloys are useful for engineering applications largely due to their high strength. Recently, materials scientists have discovered that this strength is further enhanced by so-called "nano-structured materials". These are often the same alloys as conventional metals, but with special microstructural features refined to the nanometer-scale. One finds, however, that the primary mechanisms governing strength and ductility are different in nano-structured materials than in conventional ones. This new physics is not well understood, but occurs on length scales accessible to both modern atomistic simulation and nano-experiments. It is a unique regime where a direct link between simulation and experimentation is possible.