Editors: | F. Kongoli, F. Marquis, S. Kalogirou, B. Raveau, A. Tressaud, H. Kageyama, A. Varez, R. Martins. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 154 pages |
ISBN: | 978-1-989820-34-6 (CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Dealloying, or chemically etching a material to selectively remove one or more less- noble components from the base metal, appears as an attractive process to generate metal networks for unique materials, which are in demand with modern technologies in biochemistry and medicine, catalysis, electrochemical energetics, etc. [1];[2]. Progress in this area were recently been described in Ref. [3].
The effect of duration time and composition on the microstructure and morphology of ultraporous iron was studied by electrochemical dealloying (selective anodic dissolution) of iron-manganese alloys (Mn wt% = 33; 67) in a molten equimolar mixture of NaCl-KCl and NaCl-KCl-CsCl eutectic. The possibility of electrochemical fabrication of ultraporous iron in the percolation mode at the temperature above the recrystallization annealing of steel was shown. Voltammograms (CV) were measured, and the range of potentials for the selective manganese dissolution in the specified equimolar mixture at a temperature of 700-750 ° C was found. The exposure time at a potential of 0.1 V is about an hour for the formation of a characteristic bi-continuous percolation structure of pores and ligaments. It was found that, during dealloying of ferromanganese with a Mn content of 33 wt%, manganese was etched out almost completely, and the ultraporous iron has much more uniform pore and ligament size.
Acknowledgments: The reported study was funded by RFBR, project number 20-33-90224