...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Intermetallics >Microstructural instability and embrittlement behaviour of an Al-lean, high-Nb gamma-TiAl-based alloy subjected to a long-term thermal exposure in air
【24h】

Microstructural instability and embrittlement behaviour of an Al-lean, high-Nb gamma-TiAl-based alloy subjected to a long-term thermal exposure in air

机译：贫铝，高Nbγ-TiAl基合金在空气中长期暴露于热的微观结构不稳定性和脆化行为

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Both ingot-cast and forged Ti-44Al-8Nb-1B alloys were exposed at 700 deg C in air for up to 10,000 h. The alpha_2 lamellae in the two conditions are found to be thermodynamically unstable and readily decompose through phase transformations of alpha_2 - > gamma, alpha_2 - > B2(omega) and alpha_2 - > B2(omega). Widespread B2(omega) forms throughout the lamellar structure, resulting in a significant increase in volume fraction after 10,000-h exposure. This is attributed to the composition similarity between the transformed and parent phases. The partition coefficients for Ti/Al/Nb between B2(omega) and alpha_2 and between B2(omega) and alpha_2 + gamma are all measured to be close to 1. The long-term exposure has induced embrittlement owing to oxygen releasing from alpha_2 decomposition. Room-temperature ductility is only 1/5 and 1/3 of the original value for the two conditions, respectively. However, no clear decreasing trend in S-N fatigue strength is observed, sug-gesting that the embrittlement effect of B2(OMEGA) on the surface crack initiation is difficult to detect.
机译：铸锭和锻造Ti-44Al-8Nb-1B合金均在700摄氏度的空气中暴露10,000小时。发现在两种条件下的α_2薄片是热力学不稳定的，并且容易通过α_2→γ，α_2→B2ω和α_2→B2ω的相变而分解。整个层状结构中形成了广泛的B2（ω）形成，导致暴露10,000小时后体积分数显着增加。这归因于转换后的相和父级相之间的成分相似性。 Ti / Al / Nb在B2ω和alpha_2之间以及在B2ω和alpha_2 +γ之间的分配系数均被测量为接近1。由于alpha_2分解释放出的氧气，长期暴露引起了脆化。两种条件下的室温延展性分别仅为原始值的1/5和1/3。然而，没有观察到S-N疲劳强度的明显下降趋势，这表明难以检测到B 2（OMEGA）对表面裂纹萌生的脆化作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号