Precipitation processes in the Beta-Titanium alloy Ti-5Al-5Mo-5V-3Cr
Precipitation processes in the Beta-Titanium alloy Ti-5Al-5Mo-5V-3Cr
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DOI：
10.1016/j.jallcom.2015.05.251
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发表时间：
2015-10-15
影响因子：
6.2
通讯作者：
Dye, David
中科院分区：
文献类型：
--
作者：
Coakley, James;Vorontsov, Vassili A.;Dye, David
在 300 摄氏度/8 小时+500 摄氏度/2 小时的两步时效热处理过程中，通过小角中子散射 (SANS) 原位研究了 Ti-5Al-5Mo-5V-3Cr-0.3Fe wt.% (Ti-5553) 中析出物的演变。第一个热处理步骤会析出 omega，与淬火材料相比，硬度相应增加约 15%。第二个热处理步骤从 omega 相中沉淀出细小的 α 相，与淬火材料相比，硬度增加了约 90%。SANS 测量通过原子探针断层扫描 (APT) 进行补充，以提供成分信息，通过异位透射电子显微镜 (TEM) 来局部确认相识别和尺寸分布，并通过 X 射线衍射 (XRD) 来进一步确认相识别。在 300 摄氏度/8 小时老化后，所有添加的溶质中的 omega 相都被耗尽。热处理。 APT 产生的 omega 相的体积分数估计约为 7%。 SANS 建模与 omega 相的盘形颗粒一致。在300℃热处理1小时至8小时期间，平均粒径从约7.5 nm增加至9.5 nm，而厚度从约4 nm增加至约5 nm。 SANS 模型使用 APT 的相组成估计 8 小时热处理的体积分数类似于 10%。 (C) 2015 Elsevier B.V. 保留所有权利。
Precipitate evolution in Ti-5Al-5Mo-5V-3Cr-0.3Fe wt.% (Ti-5553) has been studied in-situ by small angle neutron scattering (SANS) during a two step ageing heat treatment of 300 degrees C/8h+500 degrees C/2 h. The first heat treatment step precipitates omega, with a corresponding increase in hardness of similar to 15% compared to quenched material. The second heat treatment step precipitates fine scale alpha from the omega phase, with a similar to 90% increase in hardness compared to quenched material.The SANS measurements are complemented by atom probe tomography (APT) to give compositional information, ex-situ transmission electron microscopy (TEM) to confirm phase identification and size distribution locally, and X-ray diffraction (XRD) for additional confirmation of phase identification.The omega phase is depleted in all the solute additions following 300 degrees C/8 h ageing heat treatment. The volume fraction of the omega phase from APT is estimated to be similar to 7%. SANS modelling is consistent with disc shaped particles for the omega phase. The mean particle diameter increases from similar to 7.5 nm to 9.5 nm diameter between 1 h and 8 h heat treatment at 300 degrees C, while the thickness increases from similar to 4 nm to similar to 5 nm. The SANS model estimates the volume fraction to be similar to 10% for the 8 h heat treatment, using the phase compositions from APT. (C) 2015 Elsevier B.V. All rights reserved.