RT Journal Article
T1 High-temperature oxidation of CrAlYN coatings: 												Implications of the presence of Y and type of steel
A1 Rojas, T. C.
A1 Domínguez-Meister, S.
A1 Brizuela, M.
A1 Sánchez-López, J. C.
AB Nanolayered CrAlN and CrAlYN/CrAlN (average contents of Al ≈ 25 at.% and Y ≈ 1.6 at. %) coatings are deposited on M2 and 316 steel substrates and heated to 1000 °C in air for 2 h to study their oxidation mechanism, the thermal stability and the reactive element (RE) effect of yttrium. CrAlN on M2 develops a Cr2O3/Al2O3 passivation layer that preserves in high degree the fcc-CrAlN structure however iron ions leave the substrate and travel to the surface along the column boundaries. The CrAlYN/CrAlN coatings deposited on steels are not stable at 1000 °C, and the initial fcc-CrAlN phase is partially transformed to hcp-Al(O)N and Cr-Fe phases (M2) and Cr2N and Al2O3 (316). The addition of Y changes the predominant scale growth direction. Inward oxygen diffusion becomes dominant but a reduction of the oxide scale thickness as compared to CrAlN is not observed. The advanced microstructural analysis made by transmission electron microscopy combined with electron energy-loss spectroscopy determined that yttrium migrates mainly to the oxide scale (forming mixed oxides with substrate elements - V and Mo, either as dispersed particles or segregated at the grain boundaries) in M2, and to the oxide interface and column boundaries (forming Al-Y oxides and YN, respectively) in 316 steel. The benefits of addition of Y in improving the oxidation resistance are discussed comparatively with literature data. The RE effect of yttrium is thus observed to be dependent on the substrate, film architecture and composition.
SN 0257-8972
YR 2018
FD 2018-11-25
LK https://hdl.handle.net/11556/4070
UL https://hdl.handle.net/11556/4070
LA eng
NO Rojas , T C , Domínguez-Meister , S , Brizuela , M & Sánchez-López , J C 2018 , ' High-temperature oxidation of CrAlYN coatings : Implications of the presence of Y and type of steel ' , Surface and Coatings Technology , vol. 354 , pp. 203-213 . https://doi.org/10.1016/j.surfcoat.2018.09.020
NO Publisher Copyright: © 2018 Elsevier B.V.
NO European Regional Development Funds program (EU-FEDER) and Spanish Ministry of Economy, Industry and Competitiveness (projects n° MAT2015-65539-P and MAT2015-69035-REDC ), and CSIC ( 201560E013 ) are acknowledged for financial support. The authors are grateful to R. Escobar and J.A. Sánchez for performing GD-OES measurements. The lamellae preparation was conducted in the ‘Laboratorio de Microscopias Avanzadas’ at ‘Instituto de Nanociencia de Aragón-Universidad de Zaragoza’. Authors acknowledge the LMA-INA for offering access to their instruments and expertise. European Regional Development Funds program (EU-FEDER) and Spanish Ministry of Economy, Industry and Competitiveness (projects n° MAT2015-65539-P and MAT2015-69035-REDC), and CSIC (201560E013) are acknowledged for financial support. The authors are grateful to R. Escobar and J.A. Sánchez for performing GD-OES measurements. The lamellae preparation was conducted in the ‘Laboratorio de Microscopias Avanzadas’ at ‘Instituto de Nanociencia de Aragón-Universidad de Zaragoza’. Authors acknowledge the LMA-INA for offering access to their instruments and expertise.
DS TECNALIA Publications
RD 31 jul 2024