Engineered architectures of gadolinium zirconate based thermal barrier coatings subjected to hot corrosion testShow others and affiliations
2017 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 328, p. 361-370Article in journal (Refereed) Published
Abstract [en]
Gadolinium zirconate (GZ) is considered as a promising top coat candidate for high temperature TBC applications. Suspension plasma spray has shown the capability to generate a wide range of microstructures including the desirable columnar microstructure. In this study, two different TBC architectures were deposited using the axial suspension plasma spray. The first variation was a triple layered TBC comprising of thin YSZ base layer beneath a relatively porous GZ intermediate layer and a dense GZ top layer. The second variation was a composite TBC architecture of GZ and YSZ comprising of thin YSZ base layer and GZ + YSZ top layer. Cross sectional SEM analysis of the layered and composite TBCs revealed a columnar microstructure. The porosity content of the deposited TBCs was measured using two methods (Image Analysis and Water Intrusion). The as-sprayed TBCs were exposed at 900 degrees C for 8 h to a corrosive salt environment consisting of a mixture of vanadium pentoxide and sodium sulfate. XRD analysis on the as-corroded TBCs top surface showed the presence of gadolinium vanadate in both the layered and the composite TBCs. SEM/EDS analysis of the top surface and the cross-section of the layered and composite TBCs after hot corrosion test revealed the infiltration of the molten salts through the columnar gaps. The composite TBC showed a lower hot corrosion induced damage compared to the layered TBC where a considerable spallation was observed. (C) 2017 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
Elsevier, 2017. Vol. 328, p. 361-370
Keywords [en]
Gadolinium zirconate; Hot corrosion; Suspension plasma spray; Columnar microstructure
National Category
Manufacturing, Surface and Joining Technology
Identifiers
URN: urn:nbn:se:liu:diva-142965DOI: 10.1016/j.surfcoat.2017.09.005ISI: 000413376900040Scopus ID: 2-s2.0-85028920767OAI: oai:DiVA.org:liu-142965DiVA, id: diva2:1156505
Note
Funding Agencies|KK Foundation, Sweden [Dnr: 20140130]; AForsk foundation, Sweden [16-799]
2017-11-132017-11-132017-11-29Bibliographically approved