Having improved microstructures and properties of thermal expansion transparent, essentially colorless, tin-las fining the glass-ceramics

摘要

The purpose of the present application, (with the possible very interested in optical, thermal expansion and achieve characteristics) β- quartz glass-ceramics; The glass-ceramic product comprising; Relates to a process for the refinement and the ceramic product wherein the glass-ceramic precursor glass, as well as of the glass. The glass-ceramics, with the exception of inevitable traces of, and oxidation of arsenic, antimony, and no rare earth oxide oxidation, containing, the following components represented by the weight percent of the oxide, said having a composition of: 64 to 70% SiO _2, 18 to 24% of Al ₂ O _3, 4 to 5% of Li ₂ O, 0 to 0.6% of SnO _2, 1.9 to 4% of TiO _2, 1 to 2.5% of ZrO _2, 0 to 1.5% of MgO of from 0 to 3% ZnO, 0.3 to 1% of CaO, 0 to 3% of BaO, 0 to 3% of SrO, where BaO + SrO ≤ 3%, 0 to 1.5% of Na ₂ O, 0 to 2 % of K ₂ O, wherein _{0.2 ≤ (MgO + Na 2 O} + K 2 O) / Li 2 O ≤ 1, 0 to 3% of P ₂ O _5, less than 250 ppm of Fe ₂ O _3; And will be present in the β- quartz solid solution, these crystals is less than 40㎚, advantageously less than 35㎚, very advantageously has an average size of less than 30㎚.;