The effect of Mo and Ge reactive elements on high-temperature oxidation of higher manganese silicide.

Higher manganese silicide (HMS) alloys (Mn x-α Mo α Si y-β Ge β (x = 0.99–1.011, α = 0.005–0.02, y = 1.75, β = 0.005–0.01)) were studied to elucidate the effect of Mo and Ge pertaining to oxidation. Oxidation experiments were conducted using thermogravimetry and characterized using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Isoconversion experiments below 450 °C, shows that doping (up to 2 at%) raises the oxidation potential of HMS. Isothermally, the oxidation rate reduces buy one order of magnitude by doping on Mn and/or Si sites from 0.5 to 2 at%, revealing that the dopants-based oxides do not lessen the robustness of SiO 2 oxide. • The effects of Mo and Ge dopants on oxidation of HMS between 250ºC-600ºC were studied. • The dopants changed the oxidation kinetic model of the base alloy. • The long-term oxidation revealed that the Mn x − α Mo α Si y − β Ge β is stable below 400 °C. • Homogeneity of the alloys is key to improving the oxidation robustness of the alloys. [ABSTRACT FROM AUTHOR]