Microstructure of as-coated thermal barrier coatings with varying lifetimes
Abbreviated Journal Title
Surf. Coat. Technol.
microstructure; thermally grown oxide (TGO); thermal barrier coatings; (TBC); scanning transmission electron microscopy; physical vapor; deposition; MECHANISMS; SPALLATION; Materials Science, Coatings & Films; Physics, Applied
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. (C) 2003 Elsevier B.V. All rights reserved.
Surface & Coatings Technology
Article; Proceedings Paper
"Microstructure of as-coated thermal barrier coatings with varying lifetimes" (2004). Faculty Bibliography 2000s. 4242.