Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders
In this work, Al<sub>2</sub>O<sub>3</sub> nanoceramics were prepared by spark plasma sintering of amorphous powders and polycrystalline powders with similar particle sizes. Effective comparisons of sintering processes and ultimate products depending on starting powder conditi...
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2023-08-01
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| Online Access: | https://www.mdpi.com/1996-1944/16/16/5652 |
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| author | Dongjiang Zhang Rui Yu Xuelei Feng Xuncheng Guo Yongkang Yang Xiqing Xu |
| author_facet | Dongjiang Zhang Rui Yu Xuelei Feng Xuncheng Guo Yongkang Yang Xiqing Xu |
| author_sort | Dongjiang Zhang |
| collection | DOAJ |
| description | In this work, Al<sub>2</sub>O<sub>3</sub> nanoceramics were prepared by spark plasma sintering of amorphous powders and polycrystalline powders with similar particle sizes. Effective comparisons of sintering processes and ultimate products depending on starting powder conditions were explored. To ensure near-full density higher than 98% of the Al<sub>2</sub>O<sub>3</sub> nanoceramics, the threshold temperature in SPS is 1450 °C for polycrystalline Al<sub>2</sub>O<sub>3</sub> powders and 1300 °C for amorphous powders. The low SPS temperature for amorphous powders is attributed to the metastable state with high free energy of amorphous powders. The Al<sub>2</sub>O<sub>3</sub> nanoceramics prepared by amorphous powders display a mean grain size of 170 nm, and superior mechanical properties, including high bending strength of 870 MPa, Vickers hardness of 20.5 GPa and fracture toughness of 4.3 MPa∙m<sup>1/2</sup>. Furthermore, the Al<sub>2</sub>O<sub>3</sub> nanoceramics prepared by amorphous powders showed a larger dynamic strength and dynamic strain. The toughening mechanism with predominant transgranular fracture is explained based on the separation of quasi-boundaries. |
| first_indexed | 2024-03-10T23:46:20Z |
| format | Article |
| id | doaj.art-331e425da10e45d99cfa0f138a2cab36 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T23:46:20Z |
| publishDate | 2023-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-331e425da10e45d99cfa0f138a2cab362023-11-19T02:00:44ZengMDPI AGMaterials1996-19442023-08-011616565210.3390/ma16165652Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous PowdersDongjiang Zhang0Rui Yu1Xuelei Feng2Xuncheng Guo3Yongkang Yang4Xiqing Xu5Xi’an Modern Control Technology Research Institute, Xi’an 710065, ChinaXi’an Modern Control Technology Research Institute, Xi’an 710065, ChinaXi’an Modern Control Technology Research Institute, Xi’an 710065, ChinaXi’an Modern Control Technology Research Institute, Xi’an 710065, ChinaSchool of Materials Science & Engineering, Chang’an University, Xi’an 710061, ChinaSchool of Materials Science & Engineering, Chang’an University, Xi’an 710061, ChinaIn this work, Al<sub>2</sub>O<sub>3</sub> nanoceramics were prepared by spark plasma sintering of amorphous powders and polycrystalline powders with similar particle sizes. Effective comparisons of sintering processes and ultimate products depending on starting powder conditions were explored. To ensure near-full density higher than 98% of the Al<sub>2</sub>O<sub>3</sub> nanoceramics, the threshold temperature in SPS is 1450 °C for polycrystalline Al<sub>2</sub>O<sub>3</sub> powders and 1300 °C for amorphous powders. The low SPS temperature for amorphous powders is attributed to the metastable state with high free energy of amorphous powders. The Al<sub>2</sub>O<sub>3</sub> nanoceramics prepared by amorphous powders display a mean grain size of 170 nm, and superior mechanical properties, including high bending strength of 870 MPa, Vickers hardness of 20.5 GPa and fracture toughness of 4.3 MPa∙m<sup>1/2</sup>. Furthermore, the Al<sub>2</sub>O<sub>3</sub> nanoceramics prepared by amorphous powders showed a larger dynamic strength and dynamic strain. The toughening mechanism with predominant transgranular fracture is explained based on the separation of quasi-boundaries.https://www.mdpi.com/1996-1944/16/16/5652amorphousAl<sub>2</sub>O<sub>3</sub> nanoceramicsspark plasma sinteringlow temperature sinteringtransgranular fracture |
| spellingShingle | Dongjiang Zhang Rui Yu Xuelei Feng Xuncheng Guo Yongkang Yang Xiqing Xu Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders Materials amorphous Al<sub>2</sub>O<sub>3</sub> nanoceramics spark plasma sintering low temperature sintering transgranular fracture |
| title | Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders |
| title_full | Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders |
| title_fullStr | Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders |
| title_full_unstemmed | Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders |
| title_short | Enhanced Mechanical Properties of Al<sub>2</sub>O<sub>3</sub> Nanoceramics via Low Temperature Spark Plasma Sintering of Amorphous Powders |
| title_sort | enhanced mechanical properties of al sub 2 sub o sub 3 sub nanoceramics via low temperature spark plasma sintering of amorphous powders |
| topic | amorphous Al<sub>2</sub>O<sub>3</sub> nanoceramics spark plasma sintering low temperature sintering transgranular fracture |
| url | https://www.mdpi.com/1996-1944/16/16/5652 |
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