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Characterization of Thermal Barrier Coatings Produced by Various Thermal Spray Techniques Using Solid Powder, Suspension, and Solution Precursor Feedstock Material
Author(s) -
Ganvir Ashish,
Curry Nicholas,
Govindarajan Sivakumar,
Markocsan Nicolaie
Publication year - 2015
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.12472
Subject(s) - materials science , microstructure , thermal spraying , suspension (topology) , porosity , thermal barrier coating , solution precursor plasma spray , composite material , thermal conductivity , raw material , atmospheric pressure plasma , characterization (materials science) , thermal , plasma , ceramic , coating , nanotechnology , chemistry , mathematics , organic chemistry , physics , quantum mechanics , homotopy , pure mathematics , meteorology
Use of a liquid feedstock in thermal spraying (an alternative to the conventional solid powder feedstock) is receiving an increasing level of interest due to its capability to produce the advanced submicrometer/nanostructured coatings. Suspension plasma spraying ( SPS ) and solution precursor plasma spraying ( SPPS ) are those advanced thermal spraying techniques which help to feed this liquid feedstock. These techniques have shown to produce better performance thermal barrier coatings ( TBC s) than conventional thermal spraying. In this work, a comparative study was performed between SPS ‐ and SPPS ‐sprayed TBC s which then were also compared with the conventional atmospheric plasma‐sprayed ( APS ) TBCs. Experimental characterization included SEM, porosity analysis using weight difference by water infiltration, thermal conductivity measurements using laser flash analysis, and lifetime assessment using thermo‐cyclic fatigue test. It was concluded that SPS coatings can produce a microstructure with columnar type features (intermediary between the columnar and vertically cracked microstructure), whereas SPPS can produce vertically cracked microstructure. It was also shown that SPS coatings with particle size in suspension ( D 50 ) <3 μm were highly porous with lower thermal conductivity than SPPS and APS coatings. Furthermore, SPS coatings have also shown a relatively better thermal cyclic fatigue lifetime than SPPS .