The effect of sample thickness on micro-mesoscale tensile properties of 304SS, HT-9, and CuCrZr

Small scale mechanical testing has gained significant attention in recent times due to its advantages for materials research and development; however, the ability to extend small scale testing results to larger scale applications remains difficult, and questions remain with regards to quantifying macroscale prop-erties from microscale tests. In this study, 304SS, HT-9, and CuCrZr samples of various conditions were tested using the SS-J sample geometry with thicknesses ranging from 800 mu m to 30 mu m. Starting at thick-nesses below 200 mu m, significant reductions in material properties such as uniform elongation and ulti-mate tensile strength were observed. The presence and magnitude of the changes varied across material and material condition, indicating the coupling of both geometric and microstructural effects. Finite ele-ment analysis was performed on the overall test setup used, revealing potential flaws in using the SS-J and other related sample geometries to increasingly extreme sample aspect ratios. Microhardness and nanoindentation were also performed for comparison and revealed discrepancies in values at these dif-ferent length scales.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Small scale mechanical testing has gained attention for materials research, but extending the results to larger scale applications remains difficult. This study tested different materials and thicknesses, revealing significant reductions in material properties at smaller thicknesses. The changes varied across materials and indicated the coupling of geometric and microstructural effects. Finite element analysis revealed potential flaws in using certain sample geometries for extreme aspect ratios, and there were discrepancies in values at different length scales.