Contribution of Mg addition to the high temperature cyclic oxidation resistance of NiAlCr alloys

Abstract

Cyclic oxidation tests of NiAlCr-Mg (Mg = 0-3.8 at.%) alloys were carried out at 1027 degrees C under airflow. Small amount of Mg addition (1 at.%) increased the cyclic oxidation resistance while further addition of Mg increased the oxidation rate of the alloys. A distinct and continuous MgAl2O4 spinel layer formed on Mg containing alloys. Additional MgO layer formed on the alloys containing 2.5 and 3.8 at. % Mg.