Influence of Impact Damage on the Thermal Stress Distribution within the EB-PVD Thermal Barrier Coatings

Abstract:

Macroscopic holes often form on gas turbine blades surface by high velocity gas stream with some foreign impact particles during service. The influence of the impact-holes on the thermal stress distribution was investigated in this paper. The thermal stress distribution within the TBCs after impact-damages at high temperature was intensively studied by using finite element method. Analyze equivalent stress and thermal stress, it was found that the macroscopic holes on the surface of ceramic coatings could change the original temperature gradient and it transform the thermal stress distribution in the TBCs without impacting, resulting in the maximum tensile stress area expanding at the crest and promoting the generation of cracks and reducing coatings life. The impact-holes at the edge of the blades changed the former thermal stress distribution completely. The maximum thermal stress region existed in the alumina scale, severely decreases the life of thermal barrier coatings.

• Periodical: Materials Science Forum (Volume 849)
• Pages: 683-688
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.849.683
• Online since: March 2016
• Authors: Tai Hong Huang, Peng Song*, Qiang Ji, Heng Luo, Jian Sheng Lu
• Keywords: Coating Life, Finite Element Method, Thermal Barrier Coatings, Thermal Stress

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