Three-dimensional investigation of thermal barrier coatings by synchrotron-radiation computed laminography

2012 ◽  
Vol 66 (7) ◽  
pp. 471-474 ◽  
Author(s):  
V. Maurel ◽  
L. Helfen ◽  
F. N’Guyen ◽  
A. Koster ◽  
M. Di Michiel ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Thermal Barrier Coatings ◽  
Three Dimensional ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Computed Laminography

Modeling Effects of Material Properties and Three-Dimensional Surface Roughness on Thermal Barrier Coatings

2000 ◽  
Vol 645 ◽  
Author(s):  
Michael L. Glynn ◽  
K.T. Ramesh ◽  
P.K. Wright ◽  
K.J. Hemker
Keyword(s):  
Surface Roughness ◽  
Residual Stresses ◽  
Thermal Barrier Coatings ◽  
Material Properties ◽  
Bond Coat ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Dimensional Surface

ABSTRACTThermal barrier coatings (TBCs) are known to spall as a result of the residual stresses that develop during thermal cycling. TBC's are multi-layered coatings comprised of a metallic bond coat, thermally grown oxide and the ceramic top coat, all on top of a Ni-base superalloy substrate. The development of residual stresses is related to the generation of thermal, elastic and plastic strains in each of the layers. The focus of the current study is the development of a finite element analysis (FEA) that will model the development of residual stresses in these layers. Both interfacial roughness and material parameters (e.g., modulus of elasticity, coefficient of thermal expansion and stress relaxation of the bond coat) play a significant role in the development of residual stresses. The FEA developed in this work incorporates both of these effects and will be used to study the consequence of interface roughness, as measured in SEM micrographs, and material properties, that are being measured in a parallel project, on the development of these stresses. In this paper, the effect of an idealized three-dimensional surface roughness is compared to residual stresses resulting from a grooved surface formed by revolving a sinusoidal wave about an axis of symmetry. It is shown that cylindrical and flat button models give similar results, while the 3-D model results in stresses that are significantly larger than the stresses predicted in 2-D.

scholarly journals Improved the Durability of Thermal Barrier Coatings with Interface Modified by Three-Dimensional Mesh Patterns

2016 ◽  
Vol 99 (10) ◽  
pp. 3406-3410 ◽  
Author(s):  
L. Luo ◽  
X. Zhang ◽  
Z. Zou ◽  
F. Guo ◽  
H. Qi ◽  
...  
Keyword(s):  
Thermal Barrier Coatings ◽  
Three Dimensional ◽  
Thermal Barrier ◽  
Barrier Coatings

Computational Three-Dimensional Microstructure Defect Distributions in Thermal Barrier Coatings

2017 ◽  
Author(s):  
Stephanie A. Wimmer ◽  
Virginia G. DeGiorgi ◽  
Edward P. Gorzkowski ◽  
John Drazin
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Material Properties ◽  
Thermal Protection ◽  
Bulk Material ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Barrier Coatings

Thermal protection of components such as turbine blades is often done with thermal barrier coatings which are typically ceramic materials. Methods to manufacture ceramic coatings are being developed to create microstructures that optimize thermal protection without degrading mechanical properties of the coating. The coating requires sufficient mechanical properties to remain in place during loads associated with the operation of the component. The work presented in this paper is part of a broader effort that focuses on novel processing techniques. A fabrication method of interest is the inclusion of spherical micron-sized pores to scatter photons at high temperatures along with nano-sized grains to scatter phonons. Pores are sized and distributed so that mechanical strength is maintained. In the current work, yttria-stabilized zirconia (YSZ) is modeled. Three-dimensional microstructures representing YSZ are computationally generated. The defect sizes and orientations are generated to match an experimentally observed distribution. The defects are either randomly or regularly placed in the microstructural models. Stress-displacement analysis is used to determine effective bulk material properties. Comparisons are made to prior two-dimensional work and to experimental measurements available in the literature as appropriate. The influences that defect distributions and three dimensional effects have on the effective bulk material properties are quantified. This work is a preliminary step toward understanding the impacts that micron sized pores, voids and cracks have on thermal and mechanical characteristics. The goal is to facilitate optimizing the microstructure for thermal protection and strength retention.

scholarly journals Structural Analysis Applications

1989 ◽  
Vol 111 (2) ◽  
pp. 271-278 ◽  
Author(s):  
R. L. McKnight
Keyword(s):  
Structural Analysis ◽  
Thermal Barrier Coatings ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Turbine Engine ◽  
Inelastic Analysis ◽  
Breakthrough Technology ◽  
Computer Codes

The programs in the structural analysis area of the HOST program emphasized the generation of computer codes for performing three-dimensional inelastic analysis with more accuracy and less manpower. This paper presents the application of that technology to Aircraft Gas Turbine Engine (AGTE) components: combustors, turbine blades, and vanes. Previous limitations will be reviewed and the breakthrough technology highlighted. The synergism and spillover of the program will be demonstrated by reviewing applications to thermal barrier coatings analysis and the SSME HPFTP turbine blade. These applications show that this technology has increased the ability of the AGTE designer to be more innovative, productive, and accurate.

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