Designing Multiscale Porous Metal by Simple Dealloying with 3D Morphological Evolution Mechanism Revealed via X-ray Nano-tomography

Journal Article · 17 December 2019 · ACS Applied Materials and Interfaces

DOI: https://doi.org/10.1021/acsami.9b16392 · OSTI ID:1593264

Zou, Lijie  ^[1]; Ge, Mingyuan ^[2]; Zhao, Chonghang  ^[3]; Meng, Qingkun ^[4]; Wang, Hao ^[5]; Liu, Xiaoyang  ^[3]; Lin, Cheng-Hung  ^[3]; Xiao, Xianghui ^[2]; Lee, Wah-Keat ^[2]; Shen, Qiang ^[5]; Chen, Fei  ^[5]; Chen-Wiegart, Yu-chen Karen ^[6]

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1. Wuhan Univ. of Technology (China); Stony Brook Univ., NY (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Stony Brook Univ., NY (United States)
4. China Univ. of Mining and Technology, Xuzhou (China); Stony Brook Univ., NY (United States)
5. Wuhan Univ. of Technology (China)
6. Stony Brook Univ., NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Designing materials with multiscale, hierarchical structure is critical to drive the advancement of new technology. Specifically, porous metals with multiscale porosity from nanometer to micrometer sizes would lead to enhanced physical and chemical properties—the micron-sized pores can increase the effective diffusivity of ion transport within the porous media, and the nano-sized pores provide high specific surface area, enabling functionalities that are unique to nanoporous metals. A new ternary precursor alloy selection concept utilizing the different mixing enthalpies is demonstrated in this work for the design of multiscale, bimodal porous copper from a simple, one-step dealloying of Cu–Fe–Al ternary alloy. The nanoporosity in the bimodal porous structure is formed from dealloying of the Cu-rich phase, whereas the microporosity is controlled by dissolving the Fe-rich phase, determined by both the initial Fe particle size and sintering profile. In addition to advancing the materials design method, the multiscale pore formation during dealloying was directly visualized and quantified via an interrupted in situ synchrotron X-ray nano-tomography. The 3D morphological analysis on tortuosity showed that the presence of the microporosity can compensate the increase of the diffusion path length due to nanoporosity, which facilitates diffusion within the porous structure. Altogether the focus of the work is to introduce a new strategy to design multiscale porous metals with enhanced transport properties, and sheds light on the fundamental mechanisms on the 3D morphological evolution of the system using advanced synchrotron X-ray nano-tomography for future materials development and applications.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division
• Grant/Contract Number: SC0012704
• OSTI ID: 1593264
• Report Number(s): BNL-213540-2020-JAAM
• Journal Information: ACS Applied Materials and Interfaces, Vol. 12, Issue 2; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English