Effect of Y2O3 on acid resistance of alumina ceramic

This work aimed to improve the acid resistance of an alumina ceramic. Acid corrosion of alumina ceramic composed of Al2O3-CaCO3-SiO2-MgO-Y2O3 (ACSMY) was investigated in a hydrochloric-hydrofluoric acid solution at 65 °C for 30 min. The effect of Y2O3 content on sintering temperature, density, and acid solubility were discussed. The composition and microstructure of this material were analyzed. The acid solubilities of minor crystal phases (Y3Al5O12, CaAl12O19, Ca2Al2SiO7, and CaAl2Si2O8) and the effect of them on acid resistance of this alumina ceramic were studied. The results showed that Y2O3 additive can enhance density and change the type of phases. Phases with good acid resistance and dense structure lead to a crust formed on the surface of ceramic during acid corrosion. The crust can effectively protect the interior structure of the sample from acid solution, and then improve the acid resistance of the material.