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A fundamental model of cyclic instabilities in thermal barrier systems. (English) Zbl 1116.74345
Summary: Cyclic morphological instabilities in the thermally grown oxide (TGO) represent a source of failure in some thermal barrier systems. Observations and simulations have indicated that several factors interact to cause these instabilities to propagate: (i) thermal cycling; (ii) thermal expansion misfit; (iii) oxidation strain; (iv) yielding in the TGO and the bond coat; and (v) initial geometric imperfections. This study explores a fundamental understanding of the propagation phenomenon by devising a spherically symmetric model that can be solved analytically. The applicability of this model is addressed through comparison with simulations conducted for representative geometric imperfections and by analogy with the elastic/plastic indentation of a half space. Finite element analysis is used to confirm and extend the model. The analysis identifies the dependencies of the instability on the thermo-mechanical properties of the system. The crucial role of the in-plane growth strain is substantiated, as well as the requirement for bond coat yielding. It is demonstrated that yielding of the TGO is essential and is, in fact, the phenomenon that differentiates between cyclic and isothermal responses.

MSC:
74F05 Thermal effects in solid mechanics
74C05 Small-strain, rate-independent theories of plasticity (including rigid-plastic and elasto-plastic materials)
74M15 Contact in solid mechanics
74S05 Finite element methods applied to problems in solid mechanics
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[1] Ambrico, J.M.; Begley, M.R.; Jordan, E.H., Stress and shape evolution of irregularities in oxide films on elastic – plastic substrates due to thermal cycling and film growth, Acta mater., 49, 1577-1588, (2001)
[2] Begley, M.R.; Evans, A.G.; Hutchinson, J.W., Spherical impression of thin elastic films on elastic – plastic substrates, Int. J. solids struct., 36, 18, 2773, (1999) · Zbl 0952.74501
[3] Begley, M.R.; Mumm, D.R.; Evans, A.G.; Hutchinson, J.W., Analysis of a wedge impression test for measuring the interface toughness between films/coatings and ductile substrates, Acta mater., 48, 3211-3220, (2000)
[4] Bree, J., Incremental growth due to creep and plastic yielding of thin tubes subjected to internal pressure and cyclic thermal stresses, J. strain anal., 3, 122-137, (1968)
[5] DeMasi-Marcin, J.T.; Gupta, D.K., Surf. coat. technol., 68/69, 1, (1994)
[6] Evans, A.G.; Mumm, D.R.; Hutchinson, J.W.; Meier, G.H.; Pettit, F.S., Mechanisms controlling the durability of thermal barrier coatings, Progr. mater. sci., 46, 505-553, (2001)
[7] Gell, M.; Vaidyanathan, K.; Barber, B.; Cheng, J.; Jordan, E., Mechanism of spallation in platinum aluminide/electron beam physical vapor-deposited thermal barrier coatings, Metall. mater. trans., 30 A, 427-435, (1999)
[8] He, M.Y.; Evans, A.G.; Hutchinson, J.W., The ratcheting of compressed thermally grown thin films on ductile substrates, Acta mater., 48, 2593-2601, (2000)
[9] He, M.Y.; Hutchinson, J.W.; Evans, A.G., Large deformation simulations of cyclic displacement instabilities in thermal barrier systems, Acta mater., 50, 1063-1073, (2002)
[10] Johnson, C.A.; Ruud, J.A.; Bruce, R.; Wortman, D., Relationships between residual stress, microstructure and mechanical properties of electron beam physical vapor deposition thermal barrier, Surf. coat. technol., 109, 80-85, (1998)
[11] Karlsson, A.M.; Evans, A.G., A numerical model for the cyclic instability of thermally grown oxides in thermal barrier systems, Acta mater., 49, 1793-1804, (2001)
[12] Karlsson, A.M.; Levi, C.G.; Evans, A.G., A model study of displacement instabilities during cyclic oxidation, Acta mater., 50, 1263-1273, (2002)
[13] Karlsson, A.M.; Xu, T.; Evans, A.G., The displacement instability transition in thermal barrier systems, Acta mater, 50, 1211-1218, (2002)
[14] Miller, R.A., J. am. ceram. soc., 67, 517, (1984)
[15] Mumm, D.R.; Evans, A.G., On the role of imperfections in the failure of a thermal barrier coating made by electron beam deposition, Acta mater., 48, 1815-1827, (2000)
[16] Mumm, D.R.; Evans, A.G.; Spitsberg, I., Characterization of a cyclic displacement instability for a thermally grown oxide in a thermal barrier system, Acta mater., 49, 2329-2340, (2001)
[17] Olsson, M.; Giannakopoulos, A.E.; Suresh, S., Elastoplastic analysis of thermal cycling-ceramic particles in a metallic matrix, J. mech. phys. solids, 43, 1639-1671, (1995) · Zbl 0919.73059
[18] Rebello, N., Levi, C.G., 2002, in preparation.
[19] Ruud, J.A.; Bartz, A.; Borom, M.P.; Johnson, C.A., Strength degradation and failure mechanisms of electron-beam physical-vapor-deposited thermal barrier coatings, J. am. ceram. soc., 84, 1545-1552, (2001)
[20] Spitsberg, I., Mumm, D.R., Evans, A.G., 2002. On the failure mechanisms of thermal barrier coatings with diffusion aluminide bond coatings. Submitted.
[21] Stiger, M.J.; Yanar, N.M.; Topping, M.G.; Pettit, F.S.; Meier, G.H., Z. metall., 90, 1069-1078, (1999)
[22] Strangman, T.E., Thin solid films, 127, 93-105, (1985)
[23] Tolpygo, V.; Clarke, D.R., Surface rumpling of a (ni, pt)al bond coat induced by cyclic oxidation, Acta mater., 48, 3283-3293, (2000)
[24] Wright, P.K.; Evans, A.G., Mechanisms governing the performance of thermal barrier coatings, Curr. opin. solid state mater. sci., 4, 255-265, (1999)
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