Interphase Boundary, Grain Boundary, and Surface Diffusion in Al2O3-GdAlO3 Composites Determined from Bicrystal Coble Creep Experiments
Interphase Boundary, Grain Boundary, and Surface Diffusion in Al2O3-GdAlO3 Composites Determined from Bicrystal Coble Creep Experiments
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DOI：
10.1016/j.jeurceramsoc.2022.02.052
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发表时间：
2022-03
影响因子：
5.7
通讯作者：
D. Coffman;Yong Ma;C. Barr;J. Ouyang;K. Hattar;S. Dillon
中科院分区：
文献类型：
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作者：
D. Coffman;Yong Ma;C. Barr;J. Ouyang;K. Hattar;S. Dillon
采用激光局部加热技术对Al 2 O3-GdAlO 3复合材料进行了小尺度原位透射电镜Coble蠕变实验。这项工作的主要目标是隔离的Al 2 O3-GdAlO 3相间边界扩散，以了解它如何有助于复合材料的平均性能。GdAlO 3（GAP）和Al 2 O3的晶界扩散系数分别为DGb，GAP=15± 14 exp − 580，000 ±62，000 Jmol − 1 RTm 2s −1和DGB，Al 2 O3 =25± 21 exp − 542，000 ±30，000 Jmol − 1 RTm 2s −1。平均相间边界（IPB）扩散系数超过晶界扩散系数，测量值为DIPB=15± 14 exp − 559，000 ±117，000 Jmol − 1 RTm 2s −1。蠕变后的毛细管平滑实验用于确定表面（S）扩散系数，DS，Al 2 O3 =3.2x103±2.7x103exp− 539，000 ±26，000 Jmol − 1 RTm 2s −1和DS，GAP=4.6x104±7.7x10− 6 exp − 625，000 ±82，000 Jmol − 1 RTm 2s −1。这项工作证明了小规模的Coble蠕变实验的可行性，直接测量复合材料中的晶界和IPB扩散系数的单个组件。
Small-scale in situ transmission electron microscopy-based Coble creep experiments were performed on Al2O3-GdAlO3 composites using localized laser heating. A primary goal of the work was to isolate the Al2O3-GdAlO3 interphase boundary diffusivity in order to understand how it contributes to the average properties of the composite. The diffusivities of the grain boundaries (GB) of GdAlO3 (GAP) and Al2O3 were measured to be DGb,GAP=15±14exp−580,000±62,000Jmol−1RTm2s−1, and DGB,Al2O3=25±21exp−542,000±30,000Jmol−1RTm2s−1, respectively. The average interphase boundary (IPB) diffusivity exceeds that of the grain boundaries and was measured to be DIPB=15±14exp−559,000±117,000Jmol−1RTm2s−1. Capillary smoothing experiments after creep were used to determine surface (S) diffusivities, DS,Al2O3=3.2x103±2.7x103exp−539,000±26,000Jmol−1RTm2s−1 and DS,GAP=4.6x104±7.7x10−6exp−625,000±82,000Jmol−1RTm2s−1. This works demonstrates the feasibility of small-scale Coble creep experiments to directly measure individual components of grain boundary and IPB diffusivities in composites.