Mechanical Properties

Mechanical strength -- specifically hardness -- is also strongly size-dependent at the nanoscale. Nanosized copper and palladium clusters, with particle diameters in the 5-7 nm size range, have been found to have hardness values up to 500% greater than the hardness of the corresponding bulk metal. In other words, a copper or palladium sample broken down into nanoscale clusters in this size range can be up to six times harder than an ordinary bulk sample of the exact same metal, purely as a consequence of the particle size -- no change in chemical composition is involved, only a change in how the same atoms are physically organised and sized. This dramatic size-dependent increase in hardness is one of the practical mechanical advantages that motivates using nanomaterials in ap …