The contribution of grain-boundary activity to plasticity in nanocrystalline Fe - The effect of grain-boundary relaxation

Abstract

The role of grain boundaries in time-dependent plasticity of nanocrystalline Fe has been investigated. Samples were formed by ball milling of powder at room temperature, and their mechanical behavior was studied by nannoindentation. Anneals at 80°C, which do not affect the grain size, significantly affect the strain-rate sensitivity. This observation is interpreted to be a result of a contribution of grain-boundary activity to plasticity. Grain-boundary relaxation at the annealing temperature strongly influences this contribution.