Oxidation performance of Mo3Si with Al additions

The Mo3Si alloys with different aluminum contents were fabricated by the arc-melting and drop-casting technique, heat treated and then exposed to air at 700, 800, 900 and 1000 °C in order to assess their oxidation behavior. Line scan studies led to the assumption that the oxide scale thermally grown at 1000 °C was composed of SiO2 which was located closer to the alloy matrix and Al2O3 around the outer surface of the oxidized sample, while the Mo oxide volatilized at this oxidation temperature. The results also showed that the unalloyed sample (Mo3Si) underwent a pest reaction in a short time of exposure, while the sample with 16 at.% Al exhibited the best oxidation behavior, which could be attributed to the formation of SiO2 and Al2O3 in the oxide scale.