Water Vapor Corrosion Behavior of Scandium Silicates at 1400 degrees C

The corrosion behavior of scandium silicates with different scandia contents were investigated in an atmosphere of 50%H2O-50%O-2 water vapor with a total pressure of 1 atm at 1400 degrees C. The weight changes of scandium silicates as a function of annealing time were recorded to illustrate the corrosion behavior of these materials. The phases of as-prepared and corroded materials were compared by using X-ray diffraction and Fourier transform infrared spectroscopy. The results indicate that the water vapor does not corrode the scandium disilicate. The weight gain during corrosion is attributed to the hydroxylation of free scandia.