Skip to main content Accessibility help
×
Home

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

  • Michael L. Glynn (a1), K.T. Ramesh (a1), P.K. Wright (a2) and K.J. Hemker (a1)

Abstract

Thermal 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.

Copyright

References

Hide All
1. Miller, R.A., Oxidation-Based Model for Thermal Barrier Coating Life, J. Am. Ceram. Soc., 67, 517521 (1984).
2. Brindley, W.J., Properties of Plasma Sprayed Bond Coats, Thermal Barrier Coatings Workshop Proceedings, NASA Publication No. 3312 (1995).
3. Tolpygo, V.K. and Clarke, D.R., Surface Rumpling of a (Ni,Pt)Al Bond Coat Induced by Cyclic Oxidation, Acta Mater., 48, 32833293 (2000).
4. Brindley, W.J. and Whittenberger, J.D., Stress Relaxation of Low Pressure Plasma-Sprayed NiCrAlY Alloys, Mat. Sci. Eng., A163, 3341 (1993).
5. Pan, Deng, Wright, P.K. and Hemker, K.J., Measuring the Properties of Diffusion Aluminide Bond Coat Layers with Microsample Tensile Testing, MRS Conference Proceedings, this symposium, (2000).
6. Ferguson, B.L., Petrus, G.J. and Ordillas, M., A Software Tool to Design Thermal Barrier Coatings, NASA Phase I Final Report – Project No. 93–1-04.23-477 (1994).
7. Wright, P.K., Influence of Cyclic Strain on Life of a PVD TBC, Mat. Sci. Eng., A254, 191200, (1998).
8. Choi, Sung Ryul, Hutchinson, John W., Evans, A.G., Delamination of Multilayer Thermal Barrier Coatings, Mech. of Mater., 31, 431447 (1999).

Related content

Powered by UNSILO

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

  • Michael L. Glynn (a1), K.T. Ramesh (a1), P.K. Wright (a2) and K.J. Hemker (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.