Title

Microstructure Of As-Coated Thermal Barrier Coatings With Varying Lifetimes

Keywords

Microstructure; Physical vapor deposition; Scanning transmission electron microscopy; Thermal barrier coatings (TBC); Thermally grown oxide (TGO)

Abstract

The microstructures of the thermally grown oxide (TGO) in as-coated electron beam physical vapor deposited (EB-PVD) thermal barrier coatings (TBCs) were examined by scanning transmission electron microscopy (STEM) as a function of demonstrated TBC lifetime in a thermally cycled environment. As-coated TBC specimens were selected for analysis based on individual statistical significance in overall lifetime variation (i.e. early failures to long-lasting). Weibull probability distribution developed through cyclic furnace tests (CFT) served as the medium to determine statistical significance. For selected TBC specimens that represent the variation in lifetime, site-specific specimen preparation for STEM was carried out by focused ion beam (FIB) equipped with in-situ lift-out (INLO) technique. Differences in microstructure of TGO particularly in the mixed-oxide and continuous-oxide zone were examined and correlated to the lifetime characteristics of the TBCs. The TGO for durable TBC consisted of fine grained, uniformly thick, and dense mixed-oxide zone in addition to a uniform and smooth microstructural transition into the continuous oxide zone. © 2003 Elsevier B.V. All rights reserved.

Publication Date

1-30-2004

Publication Title

Surface and Coatings Technology

Volume

177-178

Number of Pages

89-96

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.surfcoat.2003.06.021

Socpus ID

1342289400 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/1342289400

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