Mechanical characterization of synthesized hierarchical porous silver through impact analysis of dealloying temperature on ligament morphology

Abstract

Hierarchical porous metals have shown great potential in applications such as catalysis and energy storage. However, the dealloying process often causes significant issues such as substantial volume shrinkage and stress corrosion cracking. This is particularly severe for thin strip-shaped hierarchical porous metals, which have poor macroscopic mechanical properties, limiting the application range and prospects of these materials. Therefore, transforming the precursor alloy from a thin strip to a bulk form is a key issue in improving the mechanical properties of hierarchical porous metals. In this study, we successfully prepared bulk three-level hierarchical porous silver (THPS), consisting of micron-sized pores (376 ± 86 μm), submicron pores (280 ± 50 nm), and nanopores (45 ± 20 nm) by combining GASAR technology with the dealloying method. Compression tests show that the mechanical properties of THPS are somewhat reduced compared to the sample before dealloying, but it still demonstrates considerable mechanical properties on a macroscopic scale (elastic modulus of 0.93 GPa and compressive strength of 107.87 MPa). Nanoindentation tests were conducted to analyze the effect of ligament size on mechanical properties. The results indicate that the mechanical properties of THPS decrease as the ligament size increases. Compared to other hierarchical porous silver materials, THPS exhibits better mechanical properties. Experimental results demonstrate that the combined method of GASAR and dealloying can enhance the mechanical properties of hierarchical porous metals, providing new ideas and methods for improving the performance of these materials.