[Kovove materialy - Metallic materials]
    Mon - January 25, 2021 - 15:24 No. of hits : 1227847 ISSN 1338-4252 (online) ISSN 0023-432X (printed)
© Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Bratislava, Slovak Republic

VOLUME 58 (2020), Issue 2

The TGO formation in overaluminized TBC obtained using plasma spray physical vapour deposition process during cyclic and isothermal oxidation
vol. 58 (2020), no. 2, pp. 111 - 119

The article presents the results of the microstructural characterization of the newly developed three-layer thermal barrier coating after isothermal oxidation tests. Bond coats were produced by the CVD-overaluminizing of previously low-pressure plasma sprayed (LPPS) MCrAlY coating. The outer ceramic layer was produced by the plasma spray physical vapour deposition method (PS-PVD). For comparison, the MCrAlY bond coat without aluminizing was produced by LPPS. As a result of the overaluminizing process, the formation of the NiAl aluminide layer was observed. Also, the porosity was observed as a result of the Kirkendall effect in the middle zone of the bond coat. Three-layer TBCs microscopic examination showed the formation of a thin and dense TGO layer formed from alumina oxide. The porosity observed on as-deposited three-layer TBCs disappeared during the cyclic oxidation test. A thicker and delaminated TGO layer was formed in a conventional two-layered thermal barrier coating. The isothermal oxidation test at 1100 °C for 1000 h shows that TGO (Thermally Grown Oxides) alumina oxide layer on the overaluminized bond coat was also significantly thinner compared to conventional LPPS-sprayed MCrAlY bond coats. It was concluded that the formation of the TGO layer in three-layer TBC is similar to that observed in diffusion aluminide coatings. The overaluminizing can improve the oxidation resistance of thermal barrier coatings produced by LPPS and PS-PVD methods.

Key words
thermal barrier coatings (TBC), aluminide coating, plasma spraying, low-pressure plasma spraying (LPPS), plasma spray physical vapour deposition (PS-PVD), oxidation, thermally grown oxides (TGO)

[open article.pdf] Full text (1521 KB)

[IMMS SAS]      UMMS SAV - Bratislava (SK) Personal data Protection   ver. 1.7.2      [go to HOME PAGE]
Full title of this journal is bilingual: Kovové materiály - Metallic Materials.
The official abbreviation in accordance with JCR ISI is Kovove Mater.

Article abstracts updated: 2021-01-15 08:18      
Articles in press revised: 2020-10-30 12:09     
Full text pdf uploaded: 2020-11-09 13:07    
Information updated: 2020-06-29 17:09   
Code last revised: 2020-06-29 16:48  

© OldSoft, 2004, …, 2021