Strain Engineering for the Kapitza Resistance of the ZrO2/α-Al2O3 and YSZ/α-Al2O3 Interfaces

来源 :固体力学学报(英文版) | 被引量 : 0次 | 上传用户:sun_sun
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The Kapitza resistance is of fundamental importance for the thermal stability of the interface between the ceramic top coat and the thermal growth oxide layer in the thermal barrier coating structure,which is widely used to protect high-temperature components in current gas turbine engines.The top coat typically consists of the ZrO2 partially stabilized by 8%Y2O3(YSZ),and the main component of the thermal growth oxide is α-Al2O3.In this work,the Kapitza resistance is found to be a small value of 0.69 m2·K/GW for the YSZ/α-A12O3 interface based on the heat dissipation simulation method.It indicates that the localization of thermal energy is rather weak,which is beneficial for the thermal stability of the YSZ/α-Al2O3 interface.This Kapitza resistance can be further reduced to 0.50 m2·K/GW by a mechanical or thermal compressive strain of 8%.To explore the underlying mechanism for this strain effect,we analyze the phonon vibration and the microscopic deformation in the interface region.It is revealed that the interface becomes denser through the compression-induced twisting of some Al-OZr and Al-OAi chemical bonds in the interface region,which is responsible for the reduction in the Kapitza resistance.The temperature effect and crystal size effect on the Kapitza resistance of the YSZ/α-Al2O3 interface are also systematically studied.These findings shall provide valuable information for further understanding of the thermal conductivity and thermal stability of the thermal barrier coating structures.
其他文献
通过Midas Civil有限元软件建立拱圈模型和拱圈-拱上结构联合作用模型,对空腹式无铰拱桥进行仿真模拟,引入联合作用系数K,运用系数k对比分析两种结构状态下的计算结果.联合作用下填料有利于拱板应力分布更趋于合理化;横桥向联合作用系数趋势基本一致,但反映出填料约束作用中间优于边缘效果,改善主拱结构的受压状态,降低了拱的挠度约10%,从而提高了拱圈稳定性.联合作用模型可全面真实地反映主拱的实际受力状态.拱上填料的存在分散集中荷载,保证均匀传递,使拱圈的内力得到削弱;现行规范却忽视了拱上结构与拱圈共同作用对
目的:对比不同方案在Hp阳性慢性胃炎患者中的应用价值.方法:90例Hp阳性慢性胃炎患者随机分组,对照组予奥美拉唑、磷酸铝凝胶、羟氨苄青霉素与克拉霉素,观察组予埃索美拉唑、胶体果胶铋胶囊、阿莫西林与呋喃唑酮,两组均持续给药4周后评估疗效.结果:观察组总有效率(97%VS85%)、幽门螺杆菌(Hp)根除率(93%VS78%)高于对照组(P<0.05).症状缓解时间(2.13±0.58天VS3.54±0.65天)和住院时间(4.11±1.05天VS6.33±1.23天)短于对照组(P0.05).结论:含铋剂方案
In this paper,a semi-discrete model based on peridynamics(PD)for engineered cementitious composites(ECCs)is applied to simulate the fracture behavior of functionally graded ECC(FGECC)beams.This is a new application of PD in ECC.Prior to simulating the cra
In this work,two typical interfaces are established for the antisymmetric plate wave by introducing linear defect in between phononic crystals with opposite valley Hall phases.The evolution of projected curves is demonstrated as the defect width increases
A novel elastic sandwich metamaterial plate with composite periodic rod core is designed,and the frequency band-gap characteristics are numerically and experimentally inves-tigated.The finite element and spectral element hybrid method(FE-SEHM)is developed
In this paper,a local surface nanocrystallization technology is used for thin-walled structures with square cross sections,and an energy absorption device of two-staged combined energy absorption structure is proposed.In virtue of the surface nanocrystall
As conducting an impact hammer testing during experimental modal analysis,the multiple impact phenomenon must be avoided.It is generally recognized that the multiple impact phenomenon is induced by the tester\'s improper operation and can be avoided thr
The peridynamic model of a solid is suitable for studying the dynamics of defects in materials.We use the bond-based peridynamic theory to propose a one-dimensional nonlocal continuum model to study a defect in equilibrium and in steady propagation.As the
Semiconductor-based electronic devices usually work under multiphysics fields rendering complex electromagnetic-thermo-mechanical coupling.In this work,we develop a penalty function method based on a finite element analysis to tackle this coupling behavio
We simulate the mechanical-chemical coupling during delithiation and relaxation of a cathode in a solid-state lithium-ion battery.Contact loss at the interface between the active particle and the solid electrolyte is considered.Uphill diffusion is observe