Performance of vacuum plasma spray and HVOF bond coatings at 900° and 1100 °C

SURFACE & COATINGS TECHNOLOGY

卷:337

Article

Lance, M. J.¹  Haynes, J. A.¹  Pint, B. A.¹ 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA

关键词: Photo-stimulated luminescence piezospectroscopy (PLPS);    Furnace cycle testing (FCT);    Bond coating;    Alumina scale;    TBC;    Directionally-solidified superalloy;   

DOI  :  10.1016/j.surfcoat.2017.12.062

来源: Elsevier

【 摘 要 】

The effects of Ti and B additions to a vacuum plasma sprayed (VPS) NiCoCrAlYHfSi bond coating on thermal barrier coating (TBC) performance were studied at 1100 degrees C and 900 degrees C and compared to high-velocity oxy-fuel (HVOF) bond coatings. Using alloy 247 substrates and air plasma sprayed Y2O3-stabilized ZrO2 top coatings, additions of B or Ti + B did not improve the average TBC lifetime in 1-h cycles at 1100 degrees C in air with 10% H2O. The addition of Ti resulted in a decrease in lifetime. Photo-stimulated luminescence spectroscopy was used to map residual stresses in the thermally-grown Al2O3 scale. At 900 degrees C, closer to a typical land based turbine operating bond coating temperature, specimens were examined after ten 500-h cycles in laboratory air and air with 10%H2O to study the effect of H2O. The addition of water vapor had little effect on the measured parabolic rate constants at 900 degrees C and a comparison of the oxide microstructures in both environments is reported.

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