On the rate-controlling mechanism during the plastic deformation of nanocrystalline Cu

Data in the literature on the effect of grain size from micrometers to nanometers on the flow stress, dislocation density, apparent activation volume and strain rate sensitivity parameters for Cu are analyzed to determine the rate-controlling mechanism. Accord occurs for the intersection of dislocations over the entire grain size range from 10 nm to 150 μm. The dislocation density and its structure and the related Friedel factor are important parameters.