Influence of Ti₃AlC₂ addition on water vapor resistance of low‐carbon Al₂O₃–C refractories

Abstract

Al 2 O 3 -C refractories are potential candidates for use in gasifiers, and they are Cr 2 O 3 -free. However, the oxidation of the carbon species and ceramic phases within the high-temperature water vapor environment may deteriorate the integrity of the working lining. Ti 3 AlC 2 has been verified as an effective antioxidant for Al 2 O 3 -C refractories in air. In this study, the structural transformation of Ti 3 AlC 2 during heat treatment and the water vapor resistance of Ti 3 AlC 2 -containing Al 2 O 3 -C refractories are investigated. The results show that the oxidation of Ti 3 AlC 2 and Si in the matrix contributes to the in situ formation of a multilayer core-shell structure of TiC-AlTi 2 O 5 -Al 6 Si 2 O 13 . These structural evolutions improve densification and stimulate pore size refinement, which enhances the mechanical properties and thermal stress resistance of the specimens. In particular, the refined pore size contributes to the significantly improved water vapor resistance at high temperatures.