A new approach to evaluate the elastic modulus of metallic foils

TL;DR

This paper introduces a straightforward method combining tensile testing, laser speckle measurement, and advanced data analysis to accurately evaluate the elastic modulus of metallic foils, emphasizing reproducibility and microstructural effects.

Contribution

It presents a novel measurement approach that improves accuracy and reproducibility of elastic modulus evaluation for metallic foils, incorporating advanced data evaluation and microstructural analysis.

Findings

Multiple loading-unloading cycles yield more consistent modulus values.

Texture and microstructure significantly influence measured elastic properties.

The method reduces measurement variability compared to traditional single-load tests.

Abstract

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 elasticmodulus obtained with a monotonic tensile procedure is compared to values obtained frommultiple 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 foilswere characterized since copper iswidely used in many industrial applications.