Effect of Ti and Cr on dispersion, structure and composition of oxide nano-particles in model ODS alloys
Effect of Ti and Cr on dispersion, structure and composition of oxide nano-particles in model ODS alloys
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DOI：
10.1016/j.actamat.2015.06.032
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发表时间：
2015-09
期刊：
影响因子：
9.4
通讯作者：
A. London;S. Santra;S. Amirthapandian;B. Panigrahi;R. M. Sarguna;S. Balaji;R. Vijay;C. S. Sundar-C.-S.-Sun
中科院分区：
文献类型：
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作者：
A. London;S. Santra;S. Amirthapandian;B. Panigrahi;R. M. Sarguna;S. Balaji;R. Vijay;C. S. Sundar-C.-S.-Sun
采用球磨和热挤压法制备了Fe-0.3Y2O3、fe - 0.2Ti - 0.3 y2o3和Fe-14Cr-0.2Ti-0.3Y2O3三种ODS模型合金，研究了Ti和Cr对纳米氧化物颗粒尺寸、分布、晶体结构和组成的影响。采用高分辨率透射电子显微镜（HRTEM）、原子探针断层扫描（APT）和同步x射线衍射（S-XRD）对合金进行表征，以确定氧化纳米颗粒样品的分布、结构和组成。Fe-Y2O3、fe - Ti - y2o3和fe - Cr - Ti - y2o3合金的中位粒径分别为9.6 nm、7.7 nm和3.7 nm，说明Ti的存在导致氧化物粒径显著减小，Cr的加入使尺寸进一步减小。在fe - 0.3Y2O3合金中，发现颗粒为bcc Y2O3，而在其他两种合金（fe - ti - 0.3Y2O3和Fe-Cr-Ti-Y2O3）中，发现氧化物颗粒在结构上与正交y2tio5和fcc Y2Ti2O7一致。详细的APT研究表明，在fe - Cr - ti - y2o3合金中，各种尺寸的氧化物颗粒周围都有Cr外壳，存在一系列的团簇组成，并且颗粒的化学性质随团簇大小而变化。我们发现，Cr的加入对颗粒的大小和化学计量都有很强的影响。
Three model ODS alloys (Fe–0.3Y2O3, Fe–0.2Ti–0.3Y2O3and Fe–14Cr–0.2Ti–0.3Y2O3) were prepared by ball milling and then hot extrusion to study the effect of Ti and Cr on the size, distribution, crystal structure and composition of the nano-oxide particles. All alloys were characterized by high resolution transmission electron microscopy (HRTEM), atom probe tomography (APT) and synchrotron-X-ray diffraction (S-XRD) to determine the distribution, structure and composition of the oxide nanoparticles samples. The median particle sizes were 9.6 nm, 7.7 nm and 3.7 nm for the Fe–Y2O3, Fe–Ti–Y2O3and Fe–Cr–Ti–Y2O3alloys, respectively, so the presence of Ti resulted in a significant reduction in oxide particle diameter and the addition of Cr gave a further reduction in size. In the Fe–0.3Y2O3alloy, the particles are found to be bcc Y2O3, whereas in the other two alloys (Fe–Ti–0.3Y2O3and Fe–Cr–Ti–Y2O3), the oxide particles were found to be structurally consistent with both orthorhombic Y2TiO5and fcc Y2Ti2O7. Detailed APT studies showed Cr shells around oxide particles of all sizes in the Fe–Cr–Ti–Y2O3alloy, that a range of cluster compositions are present and that the particle chemistry varies with cluster size. We show that the addition of Cr has a strong effect on both the size and stoichiometry of the particles.