Laser induced high temperature surface chemistry

Resumen del póster presentado a la XXXVII Reunión Bienal de la Real Sociedad Española de Química, celebrada en Donostia-San Sebastián del 26 al 30 de mayo de 2019.
Ceramic tiles are widely used as construction materials because of their outstanding mechanical properties (high strength, hardness, toughness and abrasion resistance), chemical inertness and aesthetic appearance. Concomitantly, a variety of new functionalities have been demonstrated during recent years, by developing appropriate frit and glaze compositions. Laser processing has been intensively utilized to improve surface characteristics, either applying ablative laser regimes or intense mid-IR emission beams that enable high temperature surface melting. In this context, in addition to the numerous thermal annealing procedures reported in the literature and applied to industry to modify the surface properties of ceramics, a novel Laser Furnace (LF) method has been recently patented. It enables modifying the surface finish of solids by inducing high temperature (1500-3000 °C) reactions at surfaces and interfaces, while maintaining volume temperatures at relatively low values (i.e. below 1200 °C). This paper deals with the application of this laser technology to the coloring of ceramic tiles previously deposited with either metal and oxide precursor thin films, or, alternatively with noble metal-organic layers. These layer/tile systems have been treated both, with nIR ns pulsed lasers and by cw CO2 lasers with emission in the mid-IR. The latter were coupled into a roller furnace to induce chemical processes which result in a variety of coloring effects.
The authors gratefully acknowledge funding from MICINN and AEI (ENE2017-83669-C4-1-R and MAT2016-79866-R), FEDER/EU (project SPRINT (EU H2020-FET-OPEN/0426)) and Gobierno de Aragón (research group T54_17R).