Investigation on Al-Al2O3 refractories with Al2O3-Ti2O3 raw material at evaluate temperatures

Abstract

To explore the phase evolution and performance changes of Al-Al2O3 refractories at high temperature upon adding novel Al2O3-Ti2O3 raw materials, samples with different Al2O3-Ti2O3 contents were heated at 1300 and 1500 °C under N2 atomosphere. The samples were analyzed by XRD, SEM, TG-DSC,industrial CT. The results indicate that the reaction between Ti2O3 and Al proceeds at elevated temperatures under N2, and the Ti2O3 phase transformed from Al-Ti alloy to TiN. At 1300 ℃, Ti2O3 was party reduced by Al and formed Al-Ti alloys with the unreacted Al, and the remaining Ti2O3 was present in a finely dispersed state, exhibiting fine whiskers in the matrix. When the heating temperature increaseds to 1500 ℃, the whiskers in the matrix became coarse due to the gaseous Al2O phase, and Ti2O3 transformed into TiN through Al2O(g) migration. The cold compressive strength and bending strength at ambient temperature of the heated samples were significantly improved.