Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy
Due to the effective precipitation strengthening effect of the β′ phase, Mg-Gd alloys exhibit excellent room temperature mechanical behaviors. However, when served at high temperatures, the metastable β′ phase will transform to other phases, resulting in severe performance degradation. In this study...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2022-12-01
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| Series: | Journal of Magnesium and Alloys |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213956721001602 |
| _version_ | 1827270420888289280 |
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| author | Shuxia Ouyang Guangyu Yang He Qin Chunhui Wang Shifeng Luo Wanqi Jie |
| author_facet | Shuxia Ouyang Guangyu Yang He Qin Chunhui Wang Shifeng Luo Wanqi Jie |
| author_sort | Shuxia Ouyang |
| collection | DOAJ |
| description | Due to the effective precipitation strengthening effect of the β′ phase, Mg-Gd alloys exhibit excellent room temperature mechanical behaviors. However, when served at high temperatures, the metastable β′ phase will transform to other phases, resulting in severe performance degradation. In this study, we investigated the effect of precipitation state achieved by different heat treatments on high temperature tensile and creep behaviors of the Mg-15Gd alloy by comparing the properties of the as-cast, solid-solutioned (T4) and peak-aged (T6) alloys. The results showed that the tensile mechanical properties of the T6 alloy were always highest from room temperature to 300 °C, in spite of an abnormal strength increase with temperature existed in the T4 alloy. For tensile creep properties, the T6 alloy exhibited the lowest steady creep rate below 235 °C while the T4 alloy possessed the best properties above 260 °C. Microstructure characterization revealed that the transition was caused by the stress-promoted precipitation of β′ phase in the T4 alloy and rapid phase transformation in the T6 alloy at high temperatures. At 260 °C, the calculated stress exponent n was 3.1 and 2.8 for the T4 and T6 alloys, respectively, suggesting the creep deformation mechanism was dislocation slip, which was further confirmed by the microstructure after creeping. Our findings can provide new insights into the heat treatment process of Mg-Gd alloys served at high temperatures. |
| first_indexed | 2024-04-11T00:54:11Z |
| format | Article |
| id | doaj.art-35d9b05fd8864dce9b056869c61826be |
| institution | Directory Open Access Journal |
| issn | 2213-9567 |
| language | English |
| last_indexed | 2025-03-22T05:21:09Z |
| publishDate | 2022-12-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Journal of Magnesium and Alloys |
| spelling | doaj.art-35d9b05fd8864dce9b056869c61826be2024-04-27T02:44:46ZengKeAi Communications Co., Ltd.Journal of Magnesium and Alloys2213-95672022-12-01101234593469Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloyShuxia Ouyang0Guangyu Yang1He Qin2Chunhui Wang3Shifeng Luo4Wanqi Jie5State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaCorresponding author.; State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaState Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, ChinaDue to the effective precipitation strengthening effect of the β′ phase, Mg-Gd alloys exhibit excellent room temperature mechanical behaviors. However, when served at high temperatures, the metastable β′ phase will transform to other phases, resulting in severe performance degradation. In this study, we investigated the effect of precipitation state achieved by different heat treatments on high temperature tensile and creep behaviors of the Mg-15Gd alloy by comparing the properties of the as-cast, solid-solutioned (T4) and peak-aged (T6) alloys. The results showed that the tensile mechanical properties of the T6 alloy were always highest from room temperature to 300 °C, in spite of an abnormal strength increase with temperature existed in the T4 alloy. For tensile creep properties, the T6 alloy exhibited the lowest steady creep rate below 235 °C while the T4 alloy possessed the best properties above 260 °C. Microstructure characterization revealed that the transition was caused by the stress-promoted precipitation of β′ phase in the T4 alloy and rapid phase transformation in the T6 alloy at high temperatures. At 260 °C, the calculated stress exponent n was 3.1 and 2.8 for the T4 and T6 alloys, respectively, suggesting the creep deformation mechanism was dislocation slip, which was further confirmed by the microstructure after creeping. Our findings can provide new insights into the heat treatment process of Mg-Gd alloys served at high temperatures.http://www.sciencedirect.com/science/article/pii/S2213956721001602Mg-Gd alloysPrecipitation stateHigh temperature tensile propertiesTensile creep behaviorsStress-promoted precipitation |
| spellingShingle | Shuxia Ouyang Guangyu Yang He Qin Chunhui Wang Shifeng Luo Wanqi Jie Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy Journal of Magnesium and Alloys Mg-Gd alloys Precipitation state High temperature tensile properties Tensile creep behaviors Stress-promoted precipitation |
| title | Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy |
| title_full | Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy |
| title_fullStr | Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy |
| title_full_unstemmed | Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy |
| title_short | Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy |
| title_sort | effect of the precipitation state on high temperature tensile and creep behaviors of mg 15gd alloy |
| topic | Mg-Gd alloys Precipitation state High temperature tensile properties Tensile creep behaviors Stress-promoted precipitation |
| url | http://www.sciencedirect.com/science/article/pii/S2213956721001602 |
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