Laser cutting of high-vitrified ceramic materials: development of a method using a Nd:YAG laser to avoid catastrophic breakdown

The laser cutting of a high-vitrified ceramic materials, fine porcelain stoneware tile, was studied using a Nd:YAG laser. Several conditions of laser cutting were tested and the optimum conditions of working operation were provided. The workpiece is preheated at 1000 °C to avoid any adverse effect of the high amount of glassy phase and silica which are present. The material was characterized by SEM-EDX before and after the laser cutting process to assess the variations produced and the evolution of cracks induced during the operation. The results allowed to develop a procedure to avoid the catastrophic breakdown of this material under the action of the laser. A localized thermal shock is produced due to the incidence of the cold cutting gas-jet during the process. This caused the formation of cracks whose advance was limited by the cooling of the melted material which experienced viscoplastic fluency. This material behaves like an element of crack anchorage and thus it avoids a catastrophic breakdown. The process conditions and its technological interests are discussed.