Types and compositions of crystalline glazes

The thermal and microstructural behavior of a R2O–RO–(ZnO)–Al2O3–(TiO2)–SiO2 based macro-crystalline raw glaze system

“…When the ZnO amount was decreased to 0.54 mol, the addition of 0.11 mol of TiO 2 to the ZT3 glaze also caused an amorphous behavior. It has been reported that TiO 2 is a well-known nucleating agent for zinc containing crystalline glazes [18,23,24]. However, in this ratio, TiO 2 did not promote the crystallization of the ZT3 glaze.…”

The effect of SiO2/Al2O3 ratio on the structure and microstructure of the glazes from SiO2–Al2O3–CaO–MgO–Na2O–K2O system

“…The first works of Zachariesen [7] defined the way to create a silico-oxygen and alumino-silico-oxygen framework, as well as the existence of two types of spatial arrangement, shortand long-range. Further work [7][8][9][10] explain the mechanisms of binding of modifiers cations with alumino-silico-oxygen framework by non-bridged oxygens. Modern research work is focused on the possibilities of modifying the properties of the glazes by influencing the degree of amorphization of the glass framework and controlled crystallization [10][11][12][13][14][15][16][17][18][19].…”

Characterization of Li–Zn–Fe crystalline phases in low temperature ceramic glaze

“…Anorthite crystals (CaO·Al 2 O 3 ·2SiO 2 ) were reported to be formed when additions of 12-20% of Al 2 O 3 were made. 3 Another effect of iron oxide crystals appears at lower temperature resulting in the so-called aventurine crystalline glaze, which is traditionally obtained when using lead oxide at lower firing temperatures. Through the use of lead-free Na 2 O-B 2 O 3 -SiO 2 frit, the iron-aventurine glaze with a crystalline effect from hematite was reported to be obtained in the temperature range 1000-1300 • C. 4 A low firing temperature glaze without lead oxide can be produced by adding alkali and alkaline earth oxides such as Na 2 O, K 2 O, Li 2 O, CaO and MgO.…”

“…8 It was considered that coloring additives such as, Fe 2 O 3 did not have as much effect as alkali and alkaline earth oxides on the crystallization of willemite since crystals continued to grow in the colored matrix. 3 The effect of iron oxide content on crystallization of the glass ceramic glaze has also been studied. 9 The crystalline phases of franklinite (ZnFe 2 O 4 ) and hematite (Fe 2 O 3 ) were obtained and their relative amounts depended on the iron content in the frit mixture.…”