The effect of scale levels of rotational plastic deformation modes on the strain resistance of polycrystals

Experiments on polycrystalline lead alloys with different states of grain volumes and boundaries under tension in a wide range of test temperatures have been performed. The qualitative and quantitative characteristics of the grain size dependence of the strain resistance of the examined materials are shown to be substantially affected by the development of rotational plastic deformation modes at different scale levels. This effect must be accounted for in the interpretation of the parameters of the Hall-Petch equation in the framework of the multiscale approach employed in physical mesomechanics.