Sodium Sulfate Hot Corrosion of Silicon Carbide Fiber-Reinforced CalciumAluminosilicate

摘要

The effects of sodium sulfate hot corrosion on the microstructure of siliconcarbide fiber-reinforced calcium aluminosilicate glass-ceramic matrix composite were investigated using optical microscopy, scanning electron microscopy (SEM) and x-ray diffraction (XRD). Hot corrosion of samples at 900 deg C for 50 hours in both air and argon was investigated. SEM and XRD investigations of the sample exposed in air revealed a complex mixture of wollastonite, nepheline and albite whereas exposure in argon showed pseudowollastonite, nepheline and calcium sulfide. It was observed that the presence of Na2SO4 enhanced the oxidation of the silicon carbide fiber to silica which further reacted to form the products of corrosion. jg p.2.