Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3
The synthesis of high-purity Mn+1AXn (MAX) phase ceramics in the Hf-Al-C ternary system from near-stoichiometric feedstock powder mixtures has been exceptionally challenging due to the rapid concurrent formation of persistent, ultrafine HfC impurities. This work synthesized ceramics containing the n...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-06-01
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| Series: | Open Ceramics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666539524000488 |
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| author | Nick Goossens Bensu Tunca Konstantina Lambrinou Jozef Vleugels |
| author_facet | Nick Goossens Bensu Tunca Konstantina Lambrinou Jozef Vleugels |
| author_sort | Nick Goossens |
| collection | DOAJ |
| description | The synthesis of high-purity Mn+1AXn (MAX) phase ceramics in the Hf-Al-C ternary system from near-stoichiometric feedstock powder mixtures has been exceptionally challenging due to the rapid concurrent formation of persistent, ultrafine HfC impurities. This work synthesized ceramics containing the nanolaminated Hf5Al2C3 ‘superstructure’, showing that it comprises alternating Hf2AlC and Hf3AlC2 atomic stackings. For the first time, the Hf5Al2C3 complex structure was associated with the topotactic transformation of Hf2AlC into Hf3AlC2, which is observed upon heating the powder compact to temperatures higher than 1500 °C; moreover, an inverse decomposition reaction of Hf3AlC2 into Hf2AlC was observed as result of further heating the powder compact to temperatures exceeding 1600 °C. The crystal structure and lattice parameters of the Hf5Al2C3 ‘superstructure’ were determined. MAX phase ceramics containing up to 40–45 wt% Hf3AlC2/Hf2AlC were produced with HfC as the main competing phase. The hardness and damage tolerance of these MAX phase ceramics were also evaluated. |
| first_indexed | 2024-04-24T16:25:07Z |
| format | Article |
| id | doaj.art-d72b5bb794bc4d979121768c4e990117 |
| institution | Directory Open Access Journal |
| issn | 2666-5395 |
| language | English |
| last_indexed | 2024-04-24T16:25:07Z |
| publishDate | 2024-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Open Ceramics |
| spelling | doaj.art-d72b5bb794bc4d979121768c4e9901172024-03-31T04:38:04ZengElsevierOpen Ceramics2666-53952024-06-0118100584Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3Nick Goossens0Bensu Tunca1Konstantina Lambrinou2Jozef Vleugels3Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001, Heverlee, Belgium; Corresponding author.Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001, Heverlee, BelgiumSchool of Computing and Engineering, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, United KingdomDepartment of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001, Heverlee, BelgiumThe synthesis of high-purity Mn+1AXn (MAX) phase ceramics in the Hf-Al-C ternary system from near-stoichiometric feedstock powder mixtures has been exceptionally challenging due to the rapid concurrent formation of persistent, ultrafine HfC impurities. This work synthesized ceramics containing the nanolaminated Hf5Al2C3 ‘superstructure’, showing that it comprises alternating Hf2AlC and Hf3AlC2 atomic stackings. For the first time, the Hf5Al2C3 complex structure was associated with the topotactic transformation of Hf2AlC into Hf3AlC2, which is observed upon heating the powder compact to temperatures higher than 1500 °C; moreover, an inverse decomposition reaction of Hf3AlC2 into Hf2AlC was observed as result of further heating the powder compact to temperatures exceeding 1600 °C. The crystal structure and lattice parameters of the Hf5Al2C3 ‘superstructure’ were determined. MAX phase ceramics containing up to 40–45 wt% Hf3AlC2/Hf2AlC were produced with HfC as the main competing phase. The hardness and damage tolerance of these MAX phase ceramics were also evaluated.http://www.sciencedirect.com/science/article/pii/S2666539524000488Hydride powdersMAX phasesPowder metallurgyReactive hot pressingHf-Al-C systemTopotactic transformation |
| spellingShingle | Nick Goossens Bensu Tunca Konstantina Lambrinou Jozef Vleugels Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 Open Ceramics Hydride powders MAX phases Powder metallurgy Reactive hot pressing Hf-Al-C system Topotactic transformation |
| title | Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 |
| title_full | Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 |
| title_fullStr | Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 |
| title_full_unstemmed | Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 |
| title_short | Topotactic transformations in Hf-Al-C MAX phase compounds: Synthesis and characterization of nanolaminated Hf2AlC, Hf3AlC2 and Hf5Al2C3 |
| title_sort | topotactic transformations in hf al c max phase compounds synthesis and characterization of nanolaminated hf2alc hf3alc2 and hf5al2c3 |
| topic | Hydride powders MAX phases Powder metallurgy Reactive hot pressing Hf-Al-C system Topotactic transformation |
| url | http://www.sciencedirect.com/science/article/pii/S2666539524000488 |
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