Characterisation of APS TBC system during isothermal oxidation at 1100oC

• Autorzy: Swadźba L. , Moskal G. , Mendala B. , Gancarczyk T.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The purpose of presented investigations was metallographical characterization of failure modes of air plasma sprayed thermal barrier coatings system in isothermal oxidation test conditions at 1100C. Design/methodology/approach: The research allowed the characterization of microstructural changes during oxidation test of zirconia coating in area of ceramic top-layer, bond coat and superalloy substrate. The examinations were conducted on TBC's specimens after 50, 120, 500, 1000, 1500 and 2000h of exposition and encompassed a microstructural analysis with the use of macro and micro investigation-LM, SEM microscopy. Findings: It was found that the durability of commercially quality TBC system is related to progress of degradation modes of bond coat and top layer. During isothermal oxidation test, the bond coat was oxidized to form of a dens alumina and a porous mixed oxide layer between the top coat of YSZ and bond coat of NiCoCrAlY alloy. At the moment of oxidation acceleration, the process of cracks initiation and propagation was observed mainly in the mixed oxide layer near the YSZ. The observed crack propagation inducted the delamination and spallation of top coat after 1000h oxidation. Research limitations/implications: The discussed research showed that main reason of degradation in TBC system is related to development of cracks at the interface between thermally grown oxide and bond coat, within the top coat or at its interface with TGO. Practical implications: The results allow the determination of the degree of durability lost of the thermal brier coating system and specification of the time of safety operation. Originality/value: The obtained results are valuable contribution to characterization of TBC systems. They enable the identification of the degradation mechanisms, which enhances the durability and safety of high temperature operation.

Słowa kluczowe

EN

thin-thick coatings; TBC; degradation; oxidation

PL

degradacja; utlenianie

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2007
• Tom: Vol. 28, nr 12
• Strony: 757--764
• Opis fizyczny: Bibliogr. 16 poz., il., tab., wykr.

Twórcy

autor

Swadźba L.

autor

Moskal G.

autor

Mendala B.

autor

Gancarczyk T.

• Silesian University of Technology, ul. Krasińskiego 8, 40-019 Katowice, Poland,

Bibliografia

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