Effect of bond coat and substrate chemistry on the interfacial degradation of thermal barrier coatings

L. T. Wu, R. T. Wu, T. Osada, K. I. Lee, M. Bai, P. Xiao

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Despite the benefit of increased operating temperature of turbine blades, the application of thermal barrier coatings (TBC) has brought the concern of coating spallation during jet engine operations. A significant portion of past research, was therefore, devoted to detailed analysis of the interfacial degradation behavior of TBC by numerical and analytical models. Nonetheless, these models tend to overlook the influence of the degradation on the complicated nature of substrate chemical diffusion/phase transformation. As a result, the predicted TBC lifetime expressed in terms of failure criterion (i.e. thermally grown oxide thickness) often deviate largely from that obtained by real experiment. The purpose of this research work is to clarify the role of substrate chemistry on the interfacial degradation of TBC. Extensive analysis was carried out on a set of systematically prepared commercial TBC subjected to different thermal exposure times. The results clearly indicated that the interfacial adhesion is a dynamic property, which depends on the substrate chemical diffusion/phase transformation. It became evident that the early spallation observed in several β bond coat system was caused by two unique phase transformations. Furthermore, the phase transformation was shown to be closely associated with the inherent chemistry of the substrate.

Original languageEnglish
Title of host publicationSUPERALLOYS 2016 - Proceedings of the 13th International Symposium on Superalloys
EditorsMark Hardy, Eric Huron, Uwe Glatzel, Brian Griffin, Beth Lewis, Cathie Rae, Venkat Seetharaman, Sammy Tin
PublisherMinerals, Metals and Materials Society
Pages167-176
Number of pages10
ISBN (Electronic)9781118996669
DOIs
Publication statusPublished - 2016
Externally publishedYes
Event13th International Symposium on Superalloys, SUPERALLOYS 2016 - Seven Springs, United States
Duration: 2016 Sep 112016 Sep 15

Publication series

NameProceedings of the International Symposium on Superalloys
Volume2016-January

Other

Other13th International Symposium on Superalloys, SUPERALLOYS 2016
Country/TerritoryUnited States
CitySeven Springs
Period16/9/1116/9/15

Keywords

  • Interface
  • Phase transformation
  • Thermal barrier coatings

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Effect of bond coat and substrate chemistry on the interfacial degradation of thermal barrier coatings'. Together they form a unique fingerprint.

Cite this