Title

Life approximation of thermal barrier coatings via quantitative microstructural analysis

Authors

Authors

C. Bargraser; P. Mohan; K. Lee; B. Yang; J. Suk; S. Choe;Y. H. Sohn

Comments

Authors: contact us about adding a copy of your work at STARS@ucf.edu

Abbreviated Journal Title

Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process.

Keywords

Thermal barrier coatings; Microstructure; Lifetime model; Fatigue; OXIDATION-INDUCED DEGRADATION; FAILURE MECHANISMS; DAMAGE MECHANISMS; GAS-TURBINES; BOND COAT; PART II; BEHAVIOR; SYSTEMS; DURABILITY; FATIGUE; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering

Abstract

The durability of thermal barrier coatings (TBCs) can dictate the life of the hot section engine components on which they are applied. In this study, we examine the microstructural degradation of air plasma sprayed ZrO2-8 wt.% Y2O3 TBCs with a low-pressure plasma sprayed CoNiCrAlY bond coat on an IN 738LC superalloy substrate. Thermal cyclic tests were carried out in air at 1100 degrees C with a 1-, 10-, and 50-h dwell period, proceeded by a 10-min heat-up and followed by a 10-min forced-air-quench. Microstructural analyses were carried out to document the growth of the thermally grown oxide scale, the depletion of the Al-rich beta-NiAl phase in the bond coat, and the population and growth of micro-cracks near the YSZ/bond coat interface. Evolution in these microstructural features was examined with respect to the lifetime of TBCs. A lifetime approximation model was developed, via modification of Paris Law, based on the experimental data. The model predicted the TBC lifetime within 10% of the experimental lifetime. (C) 2012 Elsevier B.V. All rights reserved.

Journal Title

Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing

Volume

549

Publication Date

1-1-2012

Document Type

Article

Language

English

First Page

76

Last Page

81

WOS Identifier

WOS:000305373800011

ISSN

0921-5093

Share

COinS