Conventional two-layered structure thermal barrier coatings (TBCs) were prepared onto γ'-Ni3Al based alloy IC-6 by electron beam physical vapor deposition (EB-PVD). Isothermal oxidation and thermal cycling tests ...Conventional two-layered structure thermal barrier coatings (TBCs) were prepared onto γ'-Ni3Al based alloy IC-6 by electron beam physical vapor deposition (EB-PVD). Isothermal oxidation and thermal cycling tests were carried out to investigate the effect of Mo content at the interface between bond coat and ceramic top coat caused by diffusion. It has been found that the alloy coated with TBCs presented the lowest oxidation weight gain value for the reason that the ceramic top coat in TBC system can effectively stop Mo oxides evaporating. The life time of TBCs has close relation with Mo content at the interface between the bond coat and top coat. Spaliation of ceramic top coat occurred during thermal cyclic testing when Mo atoms accumulated at the interface up to certain amount to decline the combination between the bond coat and top coat.展开更多
Thermal barrier coatings(TBCs) have been widely applied to protect metallic components in gas turbines or aero engine against the high temperatures.In the recent decade,considerable numerical models have been built up...Thermal barrier coatings(TBCs) have been widely applied to protect metallic components in gas turbines or aero engine against the high temperatures.In the recent decade,considerable numerical models have been built up to present the thermal spray process.However,much less work has focused on the prediction of the insulation temperature to the TBCs,which is an important parameter to affect the performance of the TBCs during their applications.In the present study,a 3D finite element simulation has been carried out to predict the heat insulation behavior of the 6%～8%yittria partially stabilized zirconia coatings based on a two-layer model.Furthermore,such factors as the heat transfer mode,the thickness of the coating,properties of the coating as well as the microstructure of the coating have been numerically investigated. The significance of the finding is also discussed.展开更多
基金This work is sponsored by the National Natural Science Foundation of China (NFSC) and Specialized Research Fund for the Doctoral Program of Higher Education of China (SRFDP).
文摘Conventional two-layered structure thermal barrier coatings (TBCs) were prepared onto γ'-Ni3Al based alloy IC-6 by electron beam physical vapor deposition (EB-PVD). Isothermal oxidation and thermal cycling tests were carried out to investigate the effect of Mo content at the interface between bond coat and ceramic top coat caused by diffusion. It has been found that the alloy coated with TBCs presented the lowest oxidation weight gain value for the reason that the ceramic top coat in TBC system can effectively stop Mo oxides evaporating. The life time of TBCs has close relation with Mo content at the interface between the bond coat and top coat. Spaliation of ceramic top coat occurred during thermal cyclic testing when Mo atoms accumulated at the interface up to certain amount to decline the combination between the bond coat and top coat.
基金Projects (50771009, 50731001 and 51071013) supported by the National Natural Science Foundations of China Project (2010CB631200) supported by the National Basic Research Program of China
基金Foundation item: Project (50575220) supported by the National Natural Science Foundation of ChinaProject supported by State Key Laboratory of Engines,China
文摘在传统的热障涂层(TBCs)制备工艺的基础上,在制备热障涂层陶瓷层前,采用超音速微粒轰击技术(SFPB)改变粘结层的表面状态。采用 X 射线衍射分析仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、透射电子显微镜(TEM)和微区 Cr3+荧光光谱研究粘结层的表面结构及其 1000 °C时的高温氧化相变。粘结层表面位错密度大幅度增加,形成了大量的原子扩散通道;在高温氧化初期,粘结层中 Al 原子扩散速度的增快保证了优先形成一层稳定的α-Al2O3相;在高温氧化瞬态阶段,大量 Cr3+通过 SFPB 产生的扩散通道,形成过渡相(Al0.9Cr0.1)2O3,该过渡相间接促进了γ→θ→α相变。在高温氧化初期,热障涂层 TGO 中的残余应力先急剧增大然后减小;与高温氧化26 h 的 0.93 GPa 相比,高温氧化 310 h 的残余应力降低至 0.63 GPa。在热障涂层的 TGO 层中获得了单一、连续、致密的具有抗高温氧化能力的主相α-Al2O3,这利于进一步延长其使用寿命。
文摘Thermal barrier coatings(TBCs) have been widely applied to protect metallic components in gas turbines or aero engine against the high temperatures.In the recent decade,considerable numerical models have been built up to present the thermal spray process.However,much less work has focused on the prediction of the insulation temperature to the TBCs,which is an important parameter to affect the performance of the TBCs during their applications.In the present study,a 3D finite element simulation has been carried out to predict the heat insulation behavior of the 6%～8%yittria partially stabilized zirconia coatings based on a two-layer model.Furthermore,such factors as the heat transfer mode,the thickness of the coating,properties of the coating as well as the microstructure of the coating have been numerically investigated. The significance of the finding is also discussed.
