Title

Strain Response of Thermal Barrier Coatings Captured Under Extreme Engine Environments Through Synchrotron X-ray Diffraction

Document Type

Article

Publication Date

7-31-2014

Publication Title

Nature Communications

Abstract

The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

Comments

This material is based upon work supported by the National Science Foundation grants OISE 1157619, CMMI 1125696 and by the German Science Foundation (DFG) grant no. SFB-TRR103, Project A3. This material is additionally based upon work supported by the National Science Foundation Graduate Research Fellowship Program under grant no. 1144246. Use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the US DOE under contract no. DE-AC02- 06CH11357.

DOI

10.1038/ncomms5559

Volume

5