Retaining the Nano in Nanocrystalline Alloys

摘要

When nanocrystalline metals first became available, their remarkably high strength seemed to open up many interesting design applications, but several adverse properties were soon noted. A particularly vexing problem was a micro-structural instability that decreases strength over time. The small crystal grain size creates a large grain boundary area; the associated high interfacial energy drives coarsening (increase in grain size) that leads to softening.