Ultrahigh temperature in situ transmission electron microscopy based bicrystal coble creep in Zirconia II: Interfacial thermodynamics and transport mechanisms
Ultrahigh temperature in situ transmission electron microscopy based bicrystal coble creep in Zirconia II: Interfacial thermodynamics and transport mechanisms
复制标题
DOI：
10.1016/j.actamat.2020.08.070
复制
发表时间：
2020-11-01
期刊：
影响因子：
9.4
通讯作者：
Dillon, Shen J.
中科院分区：
文献类型：
--
作者：
Grosso, Robson L.;Vikrant, K. S. N.;Dillon, Shen J.
本工作采用应力依赖的单晶界Coble蠕变和零蠕变实验相结合的方法，测量了立方ZrO2中的界面能以及晶界点缺陷的形成和迁移体积。然后，将这些数据与附文中测量的界面扩散系数一起应用于双颗粒烧结的分析。分析表明，较大的激活体积v(*)=v(F)+v(M)主要来源于较大的迁移体积，这表明晶界限速缺陷是离域的，可能是由于电荷补偿缺陷之间的静电相互作用。在小规模实验中观察到的烧结和蠕变过程的离散性质支持这样的假设，即晶界位错是晶界点缺陷的源和汇，并在烧结和Coble蠕变过程中促进应变。双颗粒模型烧结实验表明，烧结初期的致密化遵循界面反应限速动力学。(C)2020 Acta Materialia Inc.由爱思唯尔有限公司出版。版权所有。
This work uses a combination of stress dependent single grain boundary Coble creep and zero-creep experiments to measure interfacial energies, along with grain boundary point defect formation and migration volumes in cubic ZrO2. These data, along with interfacial diffusivities measured in a companion paper are then applied to analyzing two-particle sintering. The analysis presented indicates that the large activation volume, v(*) = v(f) + v(m) primarily derives from a large migration volume and suggests that the grain boundary rate limiting defects are delocalized, possibly due to electrostatic interactions between charge compensating defects. The discrete nature of the sintering and creep process observed in the small-scale experiments supports the hypothesis that grain boundary dislocations serve as sources and sinks for grain boundary point defects and facilitate strain during sintering and Coble creep. Model two-particle sintering experiments demonstrate that initial-stage densification follows interface reaction rate-limited kinetics. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.