A new approach to evaluate the elastic modulus of metallic foils

The accurate determination of the elastic properties is non-trivial for metallic foils. The measured elastic modulus is often described in literature as significantly smaller than the respective modulus of the bulk counterparts. This paper describes a straight forward way to minimize the influence of the measurement on the calculated values using a standard tensile testing device combined with a laser speckle extensometer and advanced data evaluation. The elastic modulus obtained with a monotonic tensile procedure is compared to values obtained from multiple loading–unloading cycles in the elastic regime. The latter were found to lead to more reproducible and reasonable values with significantly smaller standard deviations. To enable interpretation of the modulus values electron backscatter diffraction and X-ray diffraction were used to emphasize the effects of texture and microstructure. Two different electrodeposited copper foils were characterized since copper is widely used in many industrial applications.