Low temperature oxidation of Cr-alloyed MoSi2

Magazine article, 2007

Cr-alloyed MOSi2 was compared with monolithic MOSi2 with respect to oxidation at 450 degrees C for 456 h. Phases formed on Cr-alloyed MOSi2 after exposure are Cr-2(MoO4)(3), MoO3, and cristobalite NOD according to X-ray diffraction results. Monolithic MOSi2 forms MoO3 and mainly amorphous SiO2. X-ray photoelectron spectroscopy indicates that the main oxidation product on the outermost surface is SiO2 for all studied samples. The samples form a relatively loose oxide but the oxide adherence improves with increasing Cr content. It is indicated that Cr addition can benefit pesting control in MOSi2.