A continuum model of plasticity, phenomenological mesoscopic field dislocation mechanics, was used to study the effect of surface passivation, grain orientation, grain boundary constraints, and film thickness on the mechanical response of multicrystalline thin films. The numerical experiments presented in this paper showed that a surface passivation layer on thin films introduces thickness dependence of the mechanical response. However, the effect of passivation decreased in films with impenetrable grain boundaries. The orientation of individual grains of the multicrystal also had a significant effect on the mechanical response. The results were in qualitative agreement with experimental observations. A primary contribution of this work was the implementation of a jump condition that enables the modelling of important limits of grain boundary constraints to plastic flow, independent of ad-hoc constitutive assumptions and interface conditions.

Mechanical Response of Multicrystalline Thin Films in Mesoscale Field Dislocation Mechanics. S.Puri, A.Das, A.Acharya: Journal of the Mechanics and Physics of Solids, 2011, 59[11], 2400-17