Optimization of High Porosity Thermal Barrier Coatings Generated with a Porosity FormerShow others and affiliations
2015 (English)In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, Vol. 24, no 4, p. 622-628Article in journal (Refereed) Published
Abstract [en]
Yttria-stabilized zirconia thermal barrier coatings are extensively used in turbine industry; however, increasing performance requirements have begun to make conventional air plasma sprayed coatings insufficient for future needs. Since the thermal conductivity of bulk material cannot be lowered easily; the design of highly porous coatings may be the most efficient way to achieve coatings with low thermal conductivity. Thus the approach of fabrication of coatings with a high porosity level based on plasma spraying of ceramic particles of dysprosia-stabilized zirconia mixed with polymer particles, has been tested. Both polymer and ceramic particles melt in plasma and after impact onto a substrate they form a coating. When the coating is subjected to heat treatment, polymer burns out and a complex structure of pores and cracks is formed. In order to obtain desired porosity level and microstructural features in coatings; a design of experiments, based on changes in spray distance, powder feeding rate, and plasma-forming atmosphere, was performed. Acquired coatings were evaluated for thermal conductivity and thermo-cyclic fatigue, and their morphology was assessed using scanning electron microscopy. It was shown that porosity level can be controlled by appropriate changes in spraying parameters.
Place, publisher, year, edition, pages
2015. Vol. 24, no 4, p. 622-628
Keywords [en]
gas turbines; high temperature application; porosity of coatings; stabilized zirconia; thermal barrier coatings (TBCs)
National Category
Other Materials Engineering Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
URN: urn:nbn:se:hv:diva-7646DOI: 10.1007/s11666-014-0214-yISI: 000351587600003Scopus ID: 2-s2.0-84925447033OAI: oai:DiVA.org:hv-7646DiVA, id: diva2:815832
Conference
2014 International Thermal Spray Conference, held May 21-23, 2014, in Barcelona, Spain,
2015-06-022015-06-012025-09-30Bibliographically approved