Laser Drilling of Porous Aluminum Silicate Ceramics

The features of laser drilling of highly porous composite ceramics consisting of aluminosilicate, glass, and a small addition of polystyrene (EPS) were studied experimentally. It was found that the formation of a liquid phase can contribute to the strengthening of ceramics. A list of factors determining the dynamics of hole formation is proposed. These include not only heating, melting, ablation, and ejection, previously known for metals and dense ceramics, but also a number of others: boiling-up of the mixture component with the lowest temperature of thermal decomposition and its departure from the affected zone; melt of less volatile components; compaction of ceramic adjoining the walls; glass transition of the liquid phase on cooling after irradiation. These effects depend on the density of the composite as well as on the viscosity of the liquefied material.