A sintering model for plasma-sprayed zirconia thermal barrier coatings. Part II: Coatings bonded to a rigid substrate
Cipitria, A., Golosnoy, I.O. and Clyne, T.W. (2009) A sintering model for plasma-sprayed zirconia thermal barrier coatings. Part II: Coatings bonded to a rigid substrate. Acta Materialia, 57, (4), 993-1003.
- Published Version
The sintering model described in Part I, which relates to free-standing plasma-sprayed thermal barrier coatings, is extended here to the case of a coating attached to a rigid substrate. Through-thickness shrinkage measurements have been carried out for coatings attached to zirconia substrates, and these experimental data are compared with model predictions. The model is then used to explore the influence of the substrate material (zirconia vs. a nickel superalloy), and of the in-plane coating stiffness. Both differential thermal expansion stresses and tensile stresses arising from the constraint imposed on in-plane shrinkage can be relaxed via two diffusional mechanisms: Coble creep and microcrack opening. This relaxation allows progression towards densification, although the process is somewhat inhibited, compared with the case of a free-standing coating. Comparison of the stored elastic strain energy with the critical strain energy release rate for interfacial cracking allows estimates to be made of whether debonding is energetically favoured.
|Keywords:||Plasma-sprayed thermal barrier coatings; Modelling; Sintering; Diffusion; Variational principle|
|Divisions:||Faculty of Physical and Applied Science > Electronics and Computer Science > EEE
|Date Deposited:||09 Feb 2009 11:34|
|Last Modified:||23 Aug 2012 03:29|
|Contributors:||Cipitria, A. (Author)
Golosnoy, I.O. (Author)
Clyne, T.W. (Author)
|Further Information:||Google Scholar|
|ISI Citation Count:||14|
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
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