Surface treatment of an Al2O3-based refractory with CO2 and high power diode lasers for improved mechanical and chemical resistance characteristics

Within both normal and corrosive (NaOH and HNO3) environmental conditions, the wear rate and wear life characteristics of an Al2O3-based refractory were greatly enhanced by means of CO2 and high power diode laser (HPDL) surface treatment. Such improvements are attributed to the fact that after laser treatment, the microstructure of the Al2O3-based refractory was altered from a porous, randomly ordered structure, to a much more dense and consolidated structure that contained fewer cracks and porosities. What is more, resulting from the different rates of solidification brought about by differences in the wavelengths of the two lasers, dissimilar microstructures were subsequently generated. Indeed, despite the fact that the glaze thickness was less, the wear life of the HPDL treated surface exceeded that of the CO2 laser treated surface in all the test environments owing to its finer, more densely packed and less cracked microstructure.