Positive Effect of Mischmetal Ce/La (Cerium and Lanthanum) on High Temperature Oxidation of Ni80Cr20 Alloys

The effect of Mischmetal Ce/La on the high temperature oxidation of the heat resistant Ni80Cr20 alloys is studied in order to increase the alloys life time at high temperature. The oxidation kinetic follows the parabolic behavior for both alloys Ni80Cr20‐0 without reactive element and Ni80Cr20‐Ce/La with reactive elements Ce/La. The presence of Ce/La elements strongly decreases the oxidation kinetic. Oxide layer is found to be very adhesive on the alloy containing the reactive elements by scratch test adhesive energy measurement. These results are discussed and correlated with the oxide microstructure, mechanical properties of oxide such stress, and chemical composition of oxide layer.