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Initiation of surface cracks in multilayer ceramic thermal barrier coatings under thermal loads

✍ Scribed by K. Kokini; Y.R. Takeuchi

Publisher
Elsevier Science
Year
1994
Tongue
English
Weight
873 KB
Volume
189
Category
Article
ISSN
0921-5093

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✦ Synopsis

The initiation of surface cracks in thick ceramic thermal barrier coatings systems was studied by using controlled experiments and the corresponding analysis. The experimental boundary conditions consisted of a concentrated heat flux at the surface of the coating and water cooling at the bottom of the substrate. The results showed that tensile stresses were formed at the surface during cooling following stress relaxation during steady state heating. A parametric study showing that a low Young's modulus and a low coefficient of thermal expansion for the coating would reduce these tensile stresses and increase its durability.

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