This article presents the influence of surface additions of nanocrystalline rare earth (RE) oxides CeO2, La2O3, and CeO2 + La2O3 on the isothermal oxidation behavior of Fe20Cr and Fe20Cr5Al at 1000 °C. Thermogravimetric studies revealed parabolic kinetics in all cases and the scale thickness on specimen surfaces varied with the nature of RE oxide. The oxidation resistance of specimens coated with two RE oxides was significantly higher than those coated with either one of the two oxides. The marked increase in the oxidation resistance of the alloys coated with two RE oxides is due to optimization of RE ion radius and RE oxide grain size/shape.
1. Huiming, J, Xiaojun, L, Linan, Z. Influence of nanometric ceria coatings on oxidation behavior of Cr at 900°C. J Rare Earths. 2007;25: 1 63–67. .
2. Huiming, J, Linan, Z, Xiaojun, L. Influence of lanthanum ion implantation on adhesive property of oxide film formed on Co-40Cr alloy. J Iron Steel Res Intl. 2008;15: 1 79–84. .
3. Fernandes, SMC, Ramanathan, LV. Influence of rare earth oxide coatings on oxidation behavior of Fe-20Cr alloys. Surf Eng. 2000;16: 4 327–332. .
4. Fernandes, SMC, Ramanathan, LV. Effect of surface deposited rare earth oxide gel characteristics on cyclic oxidation behavior of Fe20-Cr alloys. Mater Res. 2006;9: 2 199–203. .
5. Patil, S, Kuiry, SC, Seal, S. Nanocrystalline ceria imparts better high-temperature protection. Proc Royal Soc London. 2004;A 460:3569–3587.
6. Pint, B. Experimental observations in support of the dynamic-segregation theory to explain the reactive-element effect. Oxid Met. 1996;45:1 .
7. Pint, B, Garrat-Reed, AJ, Hobbs, LW. The reactive element effect in ODS FeCrAl alloys. Mater High Temp. 1995;13:3–16.