论文标题
二进制FE-20 AT。％CR合金中点缺陷和富含CR的纳米相的共同进化：使用正电子歼灭光谱和原子探针断层扫描的全面研究
Co-evolution of point defects and Cr-rich nano-phase in binary Fe-20 at.% Cr alloy: A comprehensive investigation using positron annihilation spectroscopy and atom probe tomography
论文作者
论文摘要
点缺陷在二进制Fe-20 at。％cr合金中CR-CR-CR-CR-CR-CR-CR-PRIME期分离的作用是通过定期拦截（773 K时最多1000 h）的截止时间（最高1000 h），并通过定期衰老，并通过原子概率（APTRON）和正面的Anihihihihihilation and Annihihilation（Aptron Annihihilation and nihihihilation spectrappopy（Pas）进行探测。由于Fe-20 at。％CR合金在Fe-20中的Cr浓度不断增加，因此该点缺陷在整个衰老持续时间内都起着活性作用。正面对点缺陷的贴合和自我寻求能力的近原子解决使得这一分析成为可能。 Fe和Cr之间的正电子亲和力的差异可以识别与缺陷特别相关的CR-CRICH纳米强度的差异；否则，在没有缺陷的情况下，它们将是不明智的。因此，可以分别使用APT和PAS分别在衰老的每个阶段完全表征富含CR的纳米相的时间演化以及相关点缺陷。合并的APT-PAS研究表明，富含CR的α-Prime降水是在空位-CR复合物之前充当Cr簇的成核位点的空缺配合物，进而导致由于群集硬化而引起的微硬度的早期上升。有趣的是，这伴随着点缺陷浓度的显着上升。我们的结果表明，在α-Prime的核心中存在的空缺会在衰老过程中迁移到沉淀的界面，并最终被回收，从而导致几乎没有缺陷的沉淀物。这项研究记录了点缺陷在整个衰老长度中塑造α-杆相分离的过程。
The role of point defects in temporal evolution of Cr-rich alpha-prime phase separation in binary Fe-20 at.% Cr alloy is elucidated by intercepting the long term (upto 1000 h at 773 K) aging at regular intervals and probing by a combination of atom probe tomography (APT) and positron annihilation spectroscopy (PAS). Since the Cr concentration of nano-scale α/ phase in Fe-20 at.% Cr alloy increases continually on aging, the point defects play active role throughout the aging duration. The near-atomic resolution of APT and self-seeking ability of positrons towards point defects make this analysis possible. The difference of positron affinities between Fe and Cr enables identification of the Cr-rich nano-phases that are specifically associated with defects; they would otherwise be indiscernible in the absence of defect. Thus, the temporal evolution of Cr-rich nano-phase along with the associated point defects can be fully characterized at each stage of aging using APT and PAS, respectively. The combined APT-PAS study shows that Cr-rich alpha-prime precipitation is preceded by vacancy-Cr complexes that act as nucleation sites for Cr clusters, which in turn, cause an early rise in micro-hardness due to cluster hardening. Interestingly, this is accompanied by a significant rise in point defect concentration. Our results depict that the vacancies present in the core of the alpha-prime precipitates migrate towards the precipitates interface during the course of aging and eventually get recovered resulting in virtually defect-free precipitates. This study chronicles the way the point defects shape the process of alpha-prime phase separation throughout the entire length of aging.
