| 高铌TiAl合金蠕变变形的原位观察 |
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| 引用本文： | 余 龙,宋西平,张 敏,林均品,焦泽辉,于慧臣.高铌TiAl合金蠕变变形的原位观察[J].稀有金属材料与工程,2014,43(4):881-885. |
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| 作者姓名： | 余 龙 宋西平 张 敏 林均品 焦泽辉 于慧臣 |
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| 作者单位： | 北京科技大学，北京 100083;北京科技大学，北京 100083;北京科技大学，北京 100083;北京科技大学，北京 100083;北京航空材料研究院，北京 100095;北京航空材料研究院，北京 100095 |
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| 基金项目： | 国家“973”计划项目子课题（2011CB605506） |
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| 摘 要： | 研究了近片层Ti-45Al-8Nb-0.2W-0.2B-0.1Y合金在750和800℃时短时蠕变行为,并进行了扫描电镜原位观察。结果表明:在750℃蠕变时,合金具有稳定的蠕变特征,随应力提高,稳态蠕变阶段变短,其蠕变应力指数为7.5;在800℃蠕变时,低应力下具有明显的稳态蠕变阶段,其蠕变应力指数为4.0,而高应力下几乎没有稳态蠕变,直接进入加速蠕变。SEM原位观察表明,其蠕变损伤过程是微裂纹的形成、长大及相互连接;随温度升高,裂纹扩展和连接速度变快。
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| 关 键 词： | TiAl 蠕变 应力指数 原位观察 |
In Situ Observation of High Nb Containing TiAl Alloy in Creep Deformation |
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| Yu Long,Song Xiping,Zhang Min,Lin Junpin,Jiao Zehui and Yu Huichen.In Situ Observation of High Nb Containing TiAl Alloy in Creep Deformation[J].Rare Metal Materials and Engineering,2014,43(4):881-885. |
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| Authors: | Yu Long Song Xiping Zhang Min Lin Junpin Jiao Zehui and Yu Huichen |
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| Affiliation: | University of Science and Technology Beijing, Beijing 100083, China;University of Science and Technology Beijing, Beijing 100083, China;University of Science and Technology Beijing, Beijing 100083, China;University of Science and Technology Beijing, Beijing 100083, China;Beijing Institute of Aeronautical Materials, Beijing 100095, China;Beijing Institute of Aeronautical Materials, Beijing 100095, China |
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| Abstract: | A short-term creep behavior of a nearly lamellar Ti-45Al-8Nb-0.2W-0.2B-0.1Y alloy was investigated by a constant stress tension and SEM in-situ observation at 750 oC and 800 oC. The results show that with the stress increasing, duration of the steady-state creep decreases at 750 oC and 350~470 MPa and the apparent stress exponent is 7.5. When creeping at 800 oC, the alloy exhibits a steady-state creep under low stress and the apparent stress exponent is 4.0, while there is almost no steady-state creep and the alloy becomes quickly instable under high stress. SEM in-situ observation shows that the creep damage of the alloy is composed of formation, growth and interconnection of the micro-cracks, and the speed of crack propagation and connection is faster at higher temperature. |
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| Keywords: | TiAl creep apparent stress exponent in-situ observation |
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