Physicochemical processes in the zone of local laser heating of porous aluminosilicate ceramics

Abstract

AbstractThe performed investigations have shown that the basis of the local laser heating/“drilling” of composite coarse‐pored ceramics consisting of aluminosilicates and a glass phase is the melting and ablation processes that lead to the formation of a hole. The interaction of the components of the composite in the zone of high‐temperature heating is accompanied by the formation of melt of a glass phase of new composition. The motion of the metal to the depth of a sample through pore channels‐clusters of the main ceramic material depends on the viscosity of melt (ie, on the radiation regime) and the cooling rate of the melt (ie, the thermo physical properties of the ceramics and glass phase). The development of hydrodynamic pressure in the zone of laser heating leads not only to the ejection of a part of the melt from the channel, but also to the densification of the ceramics adjacent to the walls of the vitrified channel. These effects depend to a great extent on the ceramics/glass phase ratio and on the porosity of the initial ceramics.