The effect of bond coating surface modification on the performance of atmospheric plasma spray thermal barrier coatings

SURFACE & COATINGS TECHNOLOGY

卷:378

Article; Proceedings Paper

Kane, K. A.^1,3,4  Lance, M. J.¹  Sweet, M.^2,3  Pint, B. A.¹ 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37830 USA

[2] Praxair Surface Technol, Indianapolis, IN USA

[3] Commonwealth Ctr Adv Mfg, Disputanta, VA USA

[4] Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA

关键词: Atmospheric plasma spray (APS);    Thermal barrier coating (TBC);    Thermally grown oxide (TGO);    CoNiCrAlY;    Surface modification;    Surface engineering;   

DOI  :  10.1016/j.surfcoat.2019.125042

来源: Elsevier

【 摘 要 】

Asperities in atmospheric plasma sprayed (APS) CoNiCrAlY bond coatings were observed to rapidly form spinel-type oxides growing into the APS yttria-stabilized zirconia (YSZ) top coating during isothermal exposures. To minimize these transient oxides, bond coatings were either lightly or heavily modified to remove asperities, prior to top coating deposition. After a 100 h isothermal exposure at 1100 degrees C in dry air, modified regions formed a thin, Al-rich thermally grown oxide (TGO) scale while unmodified regions formed Cr- and Ni-rich transient oxide. However, in 1-h furnace cycle testing (FCT) at 1100 degrees C, the modified bond coatings showed a reduced average lifetime compared to the specimens with unmodified bond coatings. The benefit of asperities may be to geometrically inhibit crack propagation, but the volume of transient oxide formed may also density the adjacent YSZ and further inhibit cracking.

【 授权许可】

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