Thermal properties and phase stability of Yttria-Stabilized Zirconia (YSZ) coating deposited by air plasma spray onto a Ni-base superalloy
Author
dc.contributor.author
Zambrano, D. F.
Author
dc.contributor.author
Barrios, A.
Author
dc.contributor.author
Tobon, L. E.
Author
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Serna, C.
Author
dc.contributor.author
Gómez, P.
Author
dc.contributor.author
Osorio, J. D.
Author
dc.contributor.author
Toro, A.
Admission date
dc.date.accessioned
2018-07-27T16:28:57Z
Available date
dc.date.available
2018-07-27T16:28:57Z
Publication date
dc.date.issued
2018
Cita de ítem
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Ceramics International, 44 (2018): 3625–3635
es_ES
Identifier
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10.1016/j.ceramint.2017.11.109
Identifier
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https://repositorio.uchile.cl/handle/2250/150386
Abstract
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Thermal properties and microstructure characterization of Yttria Stabilized Zirconia (YSZ) Thermal Barrier Coatings (TBCs) deposited by Air Plasma Spray (APS) onto a Ni-base superalloy (Inconel 625) were studied. Two separate sets of tests were performed. The first one consisted in Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) performed over free-standing TC samples detached from TBCs. The second one included the analysis of the cross section of samples heat treated at 1100 degrees C with holding times of 600, 1000, and 1700 h. The TC porosity was analyzed for different heat treatment conditions so that inter-lamellar, intralamellar and globular pores, as well as cracks, were identified and quantified independently. An initial porosity reduction related to inter-lamellar and intra-lamellar pores, as well as cracks, was observed during the first 600 h of heat treatment, due to sintering. However, porosity continually increased during heat treatment from 600 to 1700 h driven by volumetric changes associated to phase transformations. During this period, yttrium diffused from the metastable tetragonal phase favoring the transformation to cubic phase while monoclinic phase transformed after cooling from the yttrium-depleted tetragonal phase. Energy absorption curves and the variation of heat capacity with temperature were also determined and correlated to microstructural changes.