Develoment of glass ceramic glazes in spinel system

Ceramic tiles which are used for covering of facade or interior, consist of three different material layers. For decoration of colored body, engobes and glazes need to be opaque. Opacity could be achieved by introducing costly and imported zircon in glaze and engobe compositions. Frits are widely used semi products in glazes and engobes. If in proper glass ceramic compositions, frits can be crystallized with heat treatment to different phases that gives different function to tile. Gahnite and spinel phases that in spinel structure can be crystallized in fast firing conditions. They have a potential use as an opacifier component in compositions thanks to their high refractive index. High strength transparent glass ceramic materials can be produced by nano crystallization of spinel and gahnit phases. This thesis aimed the development of glass ceramic glazes in spinel system. Within this scope, frits were developed with whiteness values reached up to 93.9, and they have the potential for using in glaze and engobe compositions. Also, with nucleating agent addition, 80 nm diameter nano crystallization was achieved in translucent glazes successfully. Only disadvantage of these frits is color loses when they are in contact with brown and black pigments, but with the usage of properly designed decor or utilization in engobe composition, they have the potential for reducing the cost of the product.