当前位置: X-MOL 学术Acta Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Characteristics of ferroelastic domains and thermal transport limits in HfO2 alloying YTaO4 ceramics
Acta Materialia ( IF 8.3 ) Pub Date : 2023-03-20 , DOI: 10.1016/j.actamat.2023.118870
Lin Chen , Mingyu Hu , Xiaodong Zheng , Jing Feng

Low thermal conductivity and a ferroelastic tetragonal-monoclinic phase transition are essential for the use of YTaO4 in thermal barrier coatings. The phonon scattering mechanism of HfO2 alloying YTaO4 is elucidated via the analysis of microstructural characteristics, and a limit thermal conductivity (1.3 W·m−1·K−1) is achieved. Furthermore, a revised model is developed to successfully derive high-temperature phonon thermal conductivity, showing a decrease in the phonon scattering coefficient as strain field fluctuations decrease. This proves that the phonon scattering coefficient is temperature dependent. Atomic weight disorder plays a significant role in thermal conductivity reduction, whereas HfO2 alloying enhances lattice symmetry and weakens the phonon scattering, and thus mitigates thermal conductivity reduction. Additionally, domain boundary width and spacing mismatch between neighboring domains cause the scattering of phonons and further reduce the thermal conductivity. Finally, evidence of a diffusive domain boundary validates that tetragonal-monoclinic transition is a second-order process.



中文翻译:

HfO2 合金化 YTaO4 陶瓷的铁弹性畴特征和热传输极限

低热导率和铁弹性四方-单斜相变对于 YTaO 4在热障涂层中的应用至关重要。通过微观结构特征分析阐明了HfO 2合金化YTaO 4的声子散射机制,并实现了极限导热系数(1.3 W·m -1 ·K -1 )。此外,还开发了一个修改后的模型,成功推导了高温声子热导率,表明随着应变场波动的减小,声子散射系数减小。这证明声子散射系数与温度有关。原子量无序在热导率降低中起着重要作用,而 HfO2合金化增强了晶格对称性并削弱了声子散射,从而减轻了热导率的降低。此外,相邻域之间的域边界宽度和间距不匹配会导致声子散射并进一步降低热导率。最后,扩散域边界的证据证实四方-单斜转变是一个二阶过程。

更新日期:2023-03-20
down
wechat
bug