Is There a Critical Size in Nano Grained Metals for Ductile to Brittle Transition?

Nanoscale metal films and electrodes are extensively used in today’s micro and nano electronics as well as nano mechanical systems. These metal structures are usually polycrystalline in nature with nano scale grains connected to each other by grain boundaries. The small size offers large grain boundary to volume ratio that is likely to affect the metal properties significantly. Here, we discuss the role of grain size and boundaries in determining the mechanical behavior of metals, such as elasticity and yielding.