Kinetics of Decomposition in MAX Phases at Elevated Temperature
The susceptibility of MAX phases to thermal dissociation at 1300-1800 °C in high vacuum has been studied using in-situ neutron diffraction. Above 1400 °C, MAX phases decomposed to binary carbide (e.g. TiCx) or binary nitride (e.g. TiNx), primarily through the sublimation of A-elements such as Al or...
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| Format: | Journal Article |
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Institute of Materials Engineering Australasia Ltd
2011
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| Online Access: | http://hdl.handle.net/20.500.11937/34403 |
| _version_ | 1848754213182504960 |
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| author | Low, It-Meng (Jim) Pang, W. |
| author_facet | Low, It-Meng (Jim) Pang, W. |
| author_sort | Low, It-Meng (Jim) |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The susceptibility of MAX phases to thermal dissociation at 1300-1800 °C in high vacuum has been studied using in-situ neutron diffraction. Above 1400 °C, MAX phases decomposed to binary carbide (e.g. TiCx) or binary nitride (e.g. TiNx), primarily through the sublimation of A-elements such as Al or Si, which results in a porous surface layer of MXx being formed. Positive activation energies were determined for the decomposition of MAX phases except for Ti3AlC2 where negative activation energy of 71.9 kJ mol-1 was obtained due to formation of fine pores on TiCx. The kinetics of isothermal phase decomposition at 1550 °C was modelled using a modified Avrami equation. An Avrami exponent (n)of < 1.0 was determined, indicative of the highly restricted diffusion of Al or Si between the channels ofM6X octohedra. The characteristics of thermal stability and phase transition are discussed. |
| first_indexed | 2025-11-14T08:36:50Z |
| format | Journal Article |
| id | curtin-20.500.11937-34403 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:36:50Z |
| publishDate | 2011 |
| publisher | Institute of Materials Engineering Australasia Ltd |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-344032017-03-08T13:13:17Z Kinetics of Decomposition in MAX Phases at Elevated Temperature Low, It-Meng (Jim) Pang, W. The susceptibility of MAX phases to thermal dissociation at 1300-1800 °C in high vacuum has been studied using in-situ neutron diffraction. Above 1400 °C, MAX phases decomposed to binary carbide (e.g. TiCx) or binary nitride (e.g. TiNx), primarily through the sublimation of A-elements such as Al or Si, which results in a porous surface layer of MXx being formed. Positive activation energies were determined for the decomposition of MAX phases except for Ti3AlC2 where negative activation energy of 71.9 kJ mol-1 was obtained due to formation of fine pores on TiCx. The kinetics of isothermal phase decomposition at 1550 °C was modelled using a modified Avrami equation. An Avrami exponent (n)of < 1.0 was determined, indicative of the highly restricted diffusion of Al or Si between the channels ofM6X octohedra. The characteristics of thermal stability and phase transition are discussed. 2011 Journal Article http://hdl.handle.net/20.500.11937/34403 Institute of Materials Engineering Australasia Ltd restricted |
| spellingShingle | Low, It-Meng (Jim) Pang, W. Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title | Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title_full | Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title_fullStr | Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title_full_unstemmed | Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title_short | Kinetics of Decomposition in MAX Phases at Elevated Temperature |
| title_sort | kinetics of decomposition in max phases at elevated temperature |
| url | http://hdl.handle.net/20.500.11937/34403 |