Affiliation:
1. Department of Materials and Henry Royce Institute University of Manchester Manchester M13 9PL UK
2. Rolls‐Royce plc PO. Box 31 Derby DE24 8BJ UK
Abstract
AbstractCalcium‐magnesium‐aluminium‐silicate (CMAS) attack is a longstanding challenge for yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) particularly at higher engine operating temperature. Here, a novel microstructural design is reported for YSZ TBCs to mitigate CMAS attack. The design is based on a drip coating method that creates a thin layer of nanoporous Al2O3 around YSZ columnar grains produced by electron beam physical vapor deposition (EB‐PVD). The nanoporous Al2O3 enables fast crystallization of CMAS melt close to the TBC surface, in the inter‐columnar gaps, and on the column walls, thereby suppressing CMAS infiltration and preventing further degradation of the TBCs due to CMAS attack. Indentation and three‐point beam bending tests indicate that the highly porous Al2O3 only slightly stiffens the TBC but offers superior resistance against sintering in long‐term thermal exposure by reducing the intercolumnar contact. This work offers a new pathway for designing novel TBC architecture with excellent CMAS resistance, strain tolerance, and sintering resistance, which also points out new insight for assembly nanoporous ceramic in traditional ceramic structure for integrated functions.
Funder
Engineering and Physical Sciences Research Council
Innovate UK
Rolls-Royce
Subject
General Physics and Astronomy,General Engineering,Biochemistry, Genetics and Molecular Biology (miscellaneous),General Materials Science,General Chemical Engineering,Medicine (miscellaneous)