Comparison of cyclic oxidation performance of APS and EBPVD processed TBCS on IN738 with a bond coat of NiCoCrAlY powder with 0.25% Hf

Stephen Akwaboa, Monica B. Silva, Patrick Mensah, Ravinder Diwan, Douglas E. Wolfe, Shengmin Guo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve higher turbine inlet temperatures (TITs), improve turbine operating temperatures, reduce fuel consumption, increase components lives and thus lead to better turbine efficiency. Yttria-stabilized zirconia (YSZ), is an ideal candidate for TBCs as it has good thermal shock resistance, high thermal stability, low density, and low thermal conductivity. Traditionally, there are two main methods of fabricating TBCs: air plasma spray (APS) TBCs and electron beam physical vapor deposition (EBPVD) TBCs. It is the objective of this paper to study the effects of APS TBC microstructures in comparison with EBPVD TBCs deposited on NiCoCrAlYHf bond coated In738 substrate material for applications in advanced gas turbines. The bond coat NiCoCrAlY contains 0.25w% Hf which is expected to improve the reliability of standard (STD) and vertically cracked (VC) APS TBC material. TBC top coatings of 300 μrn and 600 μm thickness for both standard and VC APS TBC and 300 μn EBPVD TBC were further investigated to determine the effect of coating thickness of TBC performance. Selected test specimens were evaluated for dry and wet thermal cyclic oxidation performance. Thermal property determination of select samples was achieved using a laser flash system that measures the thermal diffusivity and specific heat capacity from which the thermal conductivity is calculated. Lastly, select YSZAl2O3 composite structures were analyzed in addition to APS and EBPVD TBC microstructure, porosity, and thermal conductivity determination using a variety of analytical techniques. A laser flash system was used to measure the thermal 'diffusivity for all the samples. A POREMASTER 33 system was used to measure the porosity of the APS and EBPVD samples.

Original languageEnglish (US)
Title of host publicationProceedings of the ASME International Mechanical Engineering Congress and Exposition 2009, IMECE 2009
PublisherAmerican Society of Mechanical Engineers (ASME)
Pages2063-2068
Number of pages6
EditionPART C
ISBN (Print)9780791843826
DOIs
StatePublished - Jan 1 2010
EventASME 2009 International Mechanical Engineering Congress and Exposition, IMECE2009 - Lake Buena Vista, FL, United States
Duration: Nov 13 2009Nov 19 2009

Publication series

NameASME International Mechanical Engineering Congress and Exposition, Proceedings
NumberPART C
Volume9

Other

OtherASME 2009 International Mechanical Engineering Congress and Exposition, IMECE2009
CountryUnited States
CityLake Buena Vista, FL
Period11/13/0911/19/09

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All Science Journal Classification (ASJC) codes

  • Mechanical Engineering

Cite this

Akwaboa, S., Silva, M. B., Mensah, P., Diwan, R., Wolfe, D. E., & Guo, S. (2010). Comparison of cyclic oxidation performance of APS and EBPVD processed TBCS on IN738 with a bond coat of NiCoCrAlY powder with 0.25% Hf. In Proceedings of the ASME International Mechanical Engineering Congress and Exposition 2009, IMECE 2009 (PART C ed., pp. 2063-2068). (ASME International Mechanical Engineering Congress and Exposition, Proceedings; Vol. 9, No. PART C). American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/IMECE2009-11901