Size dependency of mechanical properties of thin Al foil at room temperature

摘要

The dimension of the parts and the structure used in microforming has come to the scale of micrometer,however,the mechanical properties can not be deduced accordingly from their bulk counterpart.For investigating the size effect of mechanical properties,Al foils with thicknesses ranged from 10 to 80 μm are subjected to tensile deformation.The finding of the size dependence of the elongation is that the elongation decreases with the thickness decreased.The thickness dependence of the maximum stress is contrary to the result that thinner specimens are stronger.However,the relationship between the maximum stress with t/d can be established based on the local hardening model.A strain rate dependence of the flow stress is found in this work.The strain rate sensitivity in consideration of the yield stress is larger than that in consideration of the maximum stress.Both strain rate sensitivities are larger than that of the bulk aluminum.