Journal ArticleDOI
Effect of Yttrium and Lanthanum on the Tensile Creep Behavior of Aluminum Oxide
TLDR
In this paper, the tensile creep behavior of two rare-earth dopant systems, lanthanum- and yttrium-doped alumina, are compared and contrasted in order to better understand the role of oversized, isovalent cation dopants in determining creep behavior.Abstract:
The tensile creep behavior of two rare-earth dopant systems, lanthanum- and yttrium-doped alumina, are compared and contrasted in order to better understand the role of oversized, isovalent cation dopants in determining creep behavior. It was found that, despite some microstructural differences, these systems displayed qualitatively a similar improvement in creep resistance, supporting the hypothesis that creep is strongly influenced by segregation. Differences in primary creep behavior and activation energy for steady-state creep were, however, observed for these systems. Given these results, it is expected that creep behavior can be further optimized by adjusting the dopant level and by controlling the microstructure.read more
Citations
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Mechanisms controlling the durability of thermal barrier coatings
TL;DR: In this paper, the authors present relationships between the durability, the governing material properties and salient morphological features of thermal barrier coatings and show that the failure is ultimately connected to the large residual compression in the thermally grown oxide through its roles in amplifying imperfections near the interface.
Journal ArticleDOI
Grain Boundary Complexions
TL;DR: Grain boundary complexion transitions are the root cause of a wide variety of materials phenomena such as abnormal grain growth, grain boundary embrittlement and activated sintering as discussed by the authors, which have defied mechanistic explanation for years.
Journal ArticleDOI
Complexion: A new concept for kinetic engineering in materials science
TL;DR: In this paper, the existence of multiple interface complexions in a real-world material system has been proven by thermodynamics, and it has been shown that an interface complexion can be considered as a separate phase which can be made to transform into different phases with vastly different properties by chemistry and heat treatment.
Journal ArticleDOI
Grain Boundary Strengthening in Alumina by Rare Earth Impurities
James P. Buban,Katsuyuki Matsunaga,Katsuyuki Matsunaga,Jianmin Chen,Jianmin Chen,Naoya Shibata,Naoya Shibata,Wai-Yim Ching,Wai-Yim Ching,T. Yamamoto,T. Yamamoto,Yuichi Ikuhara,Yuichi Ikuhara +12 more
TL;DR: It is found that the yttrium segregates to very localized regions along the grain boundary and alters the local bonding environment, thereby strengthening the boundary against mechanical creep.
Journal ArticleDOI
Mechanics-based scaling laws for the durability of thermal barrier coatings
TL;DR: In this paper, the basic scaling relations are identified and used to gain some understanding of the relative importance of the various mechanisms that arise for application scenarios with minimal thermal cycling, based on stresses that develop because of TGO growth strains in combination with thermal expansion misfit.
References
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Journal ArticleDOI
A Model for Boundary Diffusion Controlled Creep in Polycrystalline Materials
TL;DR: In this article, the authors discussed the mechanism of creep in polycrystalline alumina based on the differences between the lattice and boundary diffusion models and showed that the boundary diffusion model is more stable than lattice diffusion model, while the grain size dependence and the numerical constant are greater.
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Creep of ceramics: Part 1 Mechanical characteristics
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Creep of ceramics
TL;DR: In this article, a wide range of experimental data on the creep of ceramics was analyzed and it was shown that there is an enhanced role of diffusion creep, and in the power-law regime, Ceramics divide into two categories with stress exponents of ∼ 5 and ∼ 3, respectively.
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Creep of duplex microstructures
TL;DR: The tensile creep behavior of two ceramic composite systems exhibiting duplex microstructures was studied relative to their single-phase constituents in the temperature and stress ranges of 1,100--1,350 C and 35--75 MPa.
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Creep of polycrystalline alumina, pure and doped with transition metal impurities
Paul A. Lessing,Ronald S. Gordon +1 more
TL;DR: Grain size effects were used to evaluate the relative contributions of aluminium lattice and oxygen grain boundary diffusion to the high temperature (1350 to 1550° C) steady state creep of polycrystalline alumina, pure and doped with transition metal impurities as mentioned in this paper.