Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying
In this study, 3D interconnected nanoporous (3DNP) TiVNbMoTa HEAs were synthesized from the (TiVNbMoTa)25Ni75 as-cast precursor alloy using the liquid metal dealloying (LMD). The as-cast precursor demonstrated the initial dendritic microstructure consisting of fcc and hcp phases. At 600 °C after 1 h...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2021-09-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785421009285 |
| _version_ | 1819129188848762880 |
|---|---|
| author | Soo-Hyun Joo I.V. Okulov H. Kato |
| author_facet | Soo-Hyun Joo I.V. Okulov H. Kato |
| author_sort | Soo-Hyun Joo |
| collection | DOAJ |
| description | In this study, 3D interconnected nanoporous (3DNP) TiVNbMoTa HEAs were synthesized from the (TiVNbMoTa)25Ni75 as-cast precursor alloy using the liquid metal dealloying (LMD). The as-cast precursor demonstrated the initial dendritic microstructure consisting of fcc and hcp phases. At 600 °C after 1 h, tiny ligaments about 10 nm thickness were homogeneously synthesized. At 900 °C, the bulk transformation intensively took place at the original precursor alloy. Specifically, the dendritic morphology of the original phases disappeared, and the fraction of fcc phase decreased from 63% to 20%. This pre-transformation behavior significantly influences the dealloying mechanism. Kurdjumov–Sachs orientation relationship (OR) governed the ligament formation at the prior fcc phase while Pitsch-Schrader (P–S) OR controlled the ligament evolution at the prior hcp phase. An unusual mechanism of two-step dealloying was observed at the fcc phase region when the dealloying rate was decreased at the reaction front. The dissolution of Ni occurs by stepwise transformations of fcc=>hcp=>bcc. The prior fcc grain was transformed to the abnormally large hcp ligaments and tiny bcc ligaments. Then, the abnormal hcp ligaments were further dealloyed to smaller bcc ligaments following the P–S OR. This study pave the way for the design of compositionally complex porous materials with a customized morphology and advanced physical properties by dealloying. |
| first_indexed | 2024-12-22T08:39:45Z |
| format | Article |
| id | doaj.art-3770d56e98d9461ab7ac2bdd4b2fea34 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-12-22T08:39:45Z |
| publishDate | 2021-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-3770d56e98d9461ab7ac2bdd4b2fea342022-12-21T18:32:15ZengElsevierJournal of Materials Research and Technology2238-78542021-09-011429452953Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloyingSoo-Hyun Joo0I.V. Okulov1H. Kato2Department of Materials Science and Engineering, Dankook University, 119 Dandae-ro, Cheonan, 31116, South Korea; Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai, 980-8577, Japan; Corresponding author.Institute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai, 980-8577, Japan; Institute of Natural Sciences and Mathematics, Ural Federal University, 620000, Ekaterinburg, Russia; Faculty of Production Engineering, University of Bremen, Badgasteiner Str. 1, 28359, Bremen, Germany; Leibniz Institute for Materials Engineering - IWT, Badgasteiner Str. 3, 28359, Bremen, GermanyInstitute for Materials Research, Tohoku University, Katahira 2-1-1, Sendai, 980-8577, JapanIn this study, 3D interconnected nanoporous (3DNP) TiVNbMoTa HEAs were synthesized from the (TiVNbMoTa)25Ni75 as-cast precursor alloy using the liquid metal dealloying (LMD). The as-cast precursor demonstrated the initial dendritic microstructure consisting of fcc and hcp phases. At 600 °C after 1 h, tiny ligaments about 10 nm thickness were homogeneously synthesized. At 900 °C, the bulk transformation intensively took place at the original precursor alloy. Specifically, the dendritic morphology of the original phases disappeared, and the fraction of fcc phase decreased from 63% to 20%. This pre-transformation behavior significantly influences the dealloying mechanism. Kurdjumov–Sachs orientation relationship (OR) governed the ligament formation at the prior fcc phase while Pitsch-Schrader (P–S) OR controlled the ligament evolution at the prior hcp phase. An unusual mechanism of two-step dealloying was observed at the fcc phase region when the dealloying rate was decreased at the reaction front. The dissolution of Ni occurs by stepwise transformations of fcc=>hcp=>bcc. The prior fcc grain was transformed to the abnormally large hcp ligaments and tiny bcc ligaments. Then, the abnormal hcp ligaments were further dealloyed to smaller bcc ligaments following the P–S OR. This study pave the way for the design of compositionally complex porous materials with a customized morphology and advanced physical properties by dealloying.http://www.sciencedirect.com/science/article/pii/S2238785421009285NanoporousHigh-entropy alloyLiquid metal dealloyingDealloying mechanismAbnormal transformation |
| spellingShingle | Soo-Hyun Joo I.V. Okulov H. Kato Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying Journal of Materials Research and Technology Nanoporous High-entropy alloy Liquid metal dealloying Dealloying mechanism Abnormal transformation |
| title | Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying |
| title_full | Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying |
| title_fullStr | Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying |
| title_full_unstemmed | Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying |
| title_short | Unusual two-step dealloying mechanism of nanoporous TiVNbMoTa high-entropy alloy during liquid metal dealloying |
| title_sort | unusual two step dealloying mechanism of nanoporous tivnbmota high entropy alloy during liquid metal dealloying |
| topic | Nanoporous High-entropy alloy Liquid metal dealloying Dealloying mechanism Abnormal transformation |
| url | http://www.sciencedirect.com/science/article/pii/S2238785421009285 |
| work_keys_str_mv | AT soohyunjoo unusualtwostepdealloyingmechanismofnanoporoustivnbmotahighentropyalloyduringliquidmetaldealloying AT ivokulov unusualtwostepdealloyingmechanismofnanoporoustivnbmotahighentropyalloyduringliquidmetaldealloying AT hkato unusualtwostepdealloyingmechanismofnanoporoustivnbmotahighentropyalloyduringliquidmetaldealloying |