Surface modification of alumina-based refractories using a xenon arc lamp

Abstract

The lifetimes of refractory bricks used to line furnaces and incinerators can be reduced as a result of degradation of the bricks by chemical and physical attack. To reduce the area of refractory surface available for attack, a xenon arc lamp has been used in this research to seal surface pores and other defects, in order to limit penetration of slag into the porous bricks. Two parameters controlling the surface melting process were examined: arc lamp power and processing scan rate. Optimisation of the processing parameters resulted in smooth, sealed surfaces on 60% Al 2O 3- and 85% Al 2O 3-based refractory furnace lining brick samples. Microstructural characterisation of the treated zone produced by the radiation of the continuous, wide wavelength spectrum (340–2100 nm) arc lamp light was carried out using a scanning electron microscope (SEM) incorporating energy dispersive analysis by X-rays (EDX). In addition, a comparison of the surface roughness and hardness between the treated and untreated brick samples was used to assess the suitability of arc lamp surface processing for improving the surface characteristics of refractory bricks.