glazuurmatrix

Glazuurmatrix, or glaze matrix, is a term used in ceramics to describe the glassy phase that forms the continuous network of a glaze on a ceramic body. It is primarily a silicate matrix created when silica and fluxes melt and fuse during firing, producing a thin, adherent layer that can seal the surface, incorporate color pigments, and protect the ware.

The matrix is built from network formers such as SiO2, and from network modifiers and fluxes including alkali and alkaline earth oxides (for example Na2O, K2O, CaO) which lower the melting temperature, adjust viscosity, and influence thermal expansion. Additional components like alumina (Al2O3) can increase chemical durability and viscosity. In some glazes, boron-containing compounds or lead compounds alter the properties of the matrix.

Function: The glazuurmatrix determines key properties of the glaze, such as melting range and viscosity at firing temperature, gloss or matte appearance, translucency, color response of metal oxides, and chemical resistance. Its thermal expansion relative to the ceramic body affects glaze fit and resistance to crazing or shivering. The matrix also hosts colorants and opacifiers within the glassy phase.

Glazes can be fully glassy, relying on the matrix alone, or partially crystalline, where crystals form within the glass while the matrix remains the primary phase (crystalline glazes). Processing involves creating a slurry, applying it to a bisque-fired body, drying, and firing to maturity; the firing schedule shapes the final microstructure and properties.

See also: Glaze chemistry, Enamel, Ceramic glaze.