The Shear Response of a Thin Aluminum Layer

Aluminum layers, 10-50 mu m thick, have been diffusion bonded to alumina blocks and subjected to simple shear in order to determine the sensitivity of shear stress versus strain response to layer thickness. No significant thickness effect on strength is observed and reversed loading tests indicate isotropic hardening. Final failure in shear is by microvoid coalescence within the sandwich layer with a void spacing comparable to the layer thickness. The significance of the results for strain gradient plasticity theory is discussed. [DOI: 10.1115/1.4002210]