Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying
Abstract Porous materials with high specific surface area, high porosity, and high electrical conductivity are promising materials for functional applications, including catalysis, sensing, and energy storage. Molten salt dealloying was recently demonstrated in microwires as an alternative method to...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-12-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-20286-5 |
| _version_ | 1828293761402142720 |
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| author | Lin-Chieh Yu Charles Clark Xiaoyang Liu Arthur Ronne Bobby Layne Phillip Halstenberg Fernando Camino Dmytro Nykypanchuk Hui Zhong Mingyuan Ge Wah-Keat Lee Sanjit Ghose Sheng Dai Xianghui Xiao James F. Wishart Yu-chen Karen Chen-Wiegart |
| author_facet | Lin-Chieh Yu Charles Clark Xiaoyang Liu Arthur Ronne Bobby Layne Phillip Halstenberg Fernando Camino Dmytro Nykypanchuk Hui Zhong Mingyuan Ge Wah-Keat Lee Sanjit Ghose Sheng Dai Xianghui Xiao James F. Wishart Yu-chen Karen Chen-Wiegart |
| author_sort | Lin-Chieh Yu |
| collection | DOAJ |
| description | Abstract Porous materials with high specific surface area, high porosity, and high electrical conductivity are promising materials for functional applications, including catalysis, sensing, and energy storage. Molten salt dealloying was recently demonstrated in microwires as an alternative method to fabricate porous structures. The method takes advantage of the selective dissolution process introduced by impurities often observed in molten salt corrosion. This work further investigates molten salt dealloying in bulk Ni–20Cr alloy in both KCl–MgCl2 and KCl–NaCl salts at 700 ℃, using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction (XRD), as well as synchrotron X-ray nano-tomography. Micro-sized pores with irregular shapes and sizes ranging from sub-micron to several microns and ligaments formed during the process, while the molten salt dealloying was found to progress several microns into the bulk materials within 1–16 h, a relatively short reaction time, enhancing the practicality of using the method for synthesis. The ligament size increased from ~ 0.7 μm to ~ 1.3 μm in KCl–MgCl2 from 1 to 16 h due to coarsening, while remaining ~ 0.4 μm in KCl–NaCl during 16 h of exposure. The XRD analysis shows that the corrosion occurred primarily near the surface of the bulk sample, and Cr2O3 was identified as a corrosion product when the reaction was conducted in an air environment (controlled amount sealed in capillaries); thus surface oxides are likely to slow the morphological coarsening rate by hindering the surface diffusion in the dealloyed structure. 3D-connected pores and grain boundary corrosion were visualized by synchrotron X-ray nano-tomography. This study provides insights into the morphological and chemical evolution of molten salt dealloying in bulk materials, with a connection to molten salt corrosion concerns in the design of next-generation nuclear and solar energy power plants. |
| first_indexed | 2024-04-13T11:25:17Z |
| format | Article |
| id | doaj.art-7287a96829a7469da7e818068e82414d |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-13T11:25:17Z |
| publishDate | 2022-12-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-7287a96829a7469da7e818068e82414d2022-12-22T02:48:42ZengNature PortfolioScientific Reports2045-23222022-12-0112111210.1038/s41598-022-20286-5Evolution of micro-pores in Ni–Cr alloys via molten salt dealloyingLin-Chieh Yu0Charles Clark1Xiaoyang Liu2Arthur Ronne3Bobby Layne4Phillip Halstenberg5Fernando Camino6Dmytro Nykypanchuk7Hui Zhong8Mingyuan Ge9Wah-Keat Lee10Sanjit Ghose11Sheng Dai12Xianghui Xiao13James F. Wishart14Yu-chen Karen Chen-Wiegart15Department of Materials Science and Chemical Engineering, Stony Brook UniversityDepartment of Materials Science and Chemical Engineering, Stony Brook UniversityDepartment of Materials Science and Chemical Engineering, Stony Brook UniversityDepartment of Materials Science and Chemical Engineering, Stony Brook UniversityChemistry Division, Brookhaven National LaboratoryDepartment of Chemistry, University of TennesseeCenter for Functional Nanomaterials, Brookhaven National LaboratoryCenter for Functional Nanomaterials, Brookhaven National LaboratoryNational Synchrotron Light Source II (NSLS-II), Brookhaven National LaboratoryNational Synchrotron Light Source II (NSLS-II), Brookhaven National LaboratoryNational Synchrotron Light Source II (NSLS-II), Brookhaven National LaboratoryNational Synchrotron Light Source II (NSLS-II), Brookhaven National LaboratoryDepartment of Chemistry, University of TennesseeNational Synchrotron Light Source II (NSLS-II), Brookhaven National LaboratoryChemistry Division, Brookhaven National LaboratoryDepartment of Materials Science and Chemical Engineering, Stony Brook UniversityAbstract Porous materials with high specific surface area, high porosity, and high electrical conductivity are promising materials for functional applications, including catalysis, sensing, and energy storage. Molten salt dealloying was recently demonstrated in microwires as an alternative method to fabricate porous structures. The method takes advantage of the selective dissolution process introduced by impurities often observed in molten salt corrosion. This work further investigates molten salt dealloying in bulk Ni–20Cr alloy in both KCl–MgCl2 and KCl–NaCl salts at 700 ℃, using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction (XRD), as well as synchrotron X-ray nano-tomography. Micro-sized pores with irregular shapes and sizes ranging from sub-micron to several microns and ligaments formed during the process, while the molten salt dealloying was found to progress several microns into the bulk materials within 1–16 h, a relatively short reaction time, enhancing the practicality of using the method for synthesis. The ligament size increased from ~ 0.7 μm to ~ 1.3 μm in KCl–MgCl2 from 1 to 16 h due to coarsening, while remaining ~ 0.4 μm in KCl–NaCl during 16 h of exposure. The XRD analysis shows that the corrosion occurred primarily near the surface of the bulk sample, and Cr2O3 was identified as a corrosion product when the reaction was conducted in an air environment (controlled amount sealed in capillaries); thus surface oxides are likely to slow the morphological coarsening rate by hindering the surface diffusion in the dealloyed structure. 3D-connected pores and grain boundary corrosion were visualized by synchrotron X-ray nano-tomography. This study provides insights into the morphological and chemical evolution of molten salt dealloying in bulk materials, with a connection to molten salt corrosion concerns in the design of next-generation nuclear and solar energy power plants.https://doi.org/10.1038/s41598-022-20286-5 |
| spellingShingle | Lin-Chieh Yu Charles Clark Xiaoyang Liu Arthur Ronne Bobby Layne Phillip Halstenberg Fernando Camino Dmytro Nykypanchuk Hui Zhong Mingyuan Ge Wah-Keat Lee Sanjit Ghose Sheng Dai Xianghui Xiao James F. Wishart Yu-chen Karen Chen-Wiegart Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying Scientific Reports |
| title | Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying |
| title_full | Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying |
| title_fullStr | Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying |
| title_full_unstemmed | Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying |
| title_short | Evolution of micro-pores in Ni–Cr alloys via molten salt dealloying |
| title_sort | evolution of micro pores in ni cr alloys via molten salt dealloying |
| url | https://doi.org/10.1038/s41598-022-20286-5 |
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