Structure analysis of precursor alloy and diffusion during dealloying of Ag-Al alloy

Runwei Zhang; Xu Wang; Zhichao Zhang; Jacob C Huang; Feng Shi; Ming Wu

doi:10.1039/c7ra12915g

Structure analysis of precursor alloy and diffusion during dealloying of Ag-Al alloy

RSC Adv. 2018 Mar 5;8(17):9462-9470. doi: 10.1039/c7ra12915g. eCollection 2018 Feb 28.

Authors

Runwei Zhang¹, Xu Wang¹, Zhichao Zhang¹, Jacob C Huang², Feng Shi¹, Ming Wu¹

Affiliations

¹ School of Mechanical Engineering, Liaoning Shihua University Fushun 113001 P. R. China wangxu@lnpu.edu.cn wx1979875@hotmail.com.
² Institute for Advanced Study, Department of Materials Science & Engineering, City University of Hong Kong Kowloon Hong Kong.

Abstract

Nanoporous silver (NPS) was fabricated by dealloying Ag-Al alloy ribbons with nominal compositions of 30, 35 and 40 at% Ag (corresponding to hypoeutectic composition, eutectic composition and hypereutectic composition, respectively). The microstructures of the Ag-Al precursor and as-dealloyed samples were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) as well as via focused ion beam (FIB) technique. We concluded that with the increase in Ag content from 30 to 40 at%, the diameter of ligament increased from 70 ± 15 nm to 115 ± 35 nm. Due to the method of crystalline solidification and the distribution of α-Al(Ag) and γ-Ag₂Al phases, the as-dealloyed Ag₃₅Al₆₅ alloy exhibited a homogeneous ligament/pore structure, whereas the microstructures of Ag₃₀Al₇₀ and Ag₄₀Al₆₀ showed thinner and coarser ligament structures, respectively.