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Isothermal Oxidation of Thermal Barrier Coatings Deposited Using LPPS, CVD, and PS-PVD Methods on MAR M247 Nickel Superalloy

Góral Marek, Kubaszek Tadeusz, Pytel Maciej

Advances in Manufacturing Science and Technology

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2020

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Vol. 44, nr 1

9--14

EN

The article presents the results of microstructural characterization of newly developed three-layer thermal barrier coating (TBC) after isothermal oxidation test. Bond coats were deposited by the overaluminizing of MCrAlY coating deposited by low-pressure plasma spraying (LPPS) process. The outer ceramic layer of yttria-stabilized zirconia was deposited by the plasma spray physical vapor deposition process. The TBCs with MCrAlY bond coat without aluminizing process was produced by LPPS as well. The isothermal oxidation test at 1,100°C for 1,000 h showed that the thickness of the thermally grown oxides alumina oxide layer on overaluminized bond coats was significantly thinner in comparison with conventional LPPS-sprayed MCrAlY bond coats. The possibility of the presence of NiAl and Ni3Al phases in the outer zone of overaluminized bond coat after the oxidation test was observed.

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Thermal barrier coatings manufactured by suspension plasma spraying - a review

Łatka L.

Advances in Materials Science

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2018

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Vol. 18, nr 3(57)

95--117

EN

Thermal barrier coatings (TBC) is one of the most intensively studied of coatings’ applications area. From 1970’s TBC are developed in two independent ways: (i) development in new materials, with lower thermal conductivity, better erosion resistance and better thermal shock resistance or (ii) development in new deposition techniques. On this field besides conventional atmospheric plasma spraying (APS) and almost conventional (because of very common use) EB-PVD method, in the past 20 years two new techniques have been developed, namely suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS). In this paper only SPS method was described, as well as, new materials, which could be used in industrial applications of TBC. Moreover, the key issues, like suspension preparation, type of suspension injection, interaction between liquid droplets and plasma jet and deposition mechanism were described.

3

Modeling of residual stresses developed in thermal barrier coatings during thermal cycling

Srivathsa B., Alam M. Z., Kamat S. V., Das D. K.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 3

869-883

EN

Thermal barrier coatings (TBCs) are widely used on Ni-based superalloy components of gas turbine engines. Although several mechanisms for the failure of the TBCs have been suggested, it is largely accepted that the durability of these coatings is primarily determined by the residual stresses that are introduced due to the growth of the TGO during operation. In the present study, the residual stress build-up in a TBC system during thermal cycling is modeled. A two-dimensional plane strain finite element analysis is carried out. The model includes both flat and undulated growth fronts for the TGO layer. The stress distribution pattern in the TBC system in the case of a planar TGO front was found to be markedly different from that of an undulated front. The ceramic layer was found to be prone to delamination at concave undulations.