PURPOSE: To obtain a glass powder having a compsn. crystallizable to yield a sintered glass ceramic having good electrical properties, dielectric and mechanical characteristics, particularly suitable for the production of electrotechnical and electronic parts and contg. hexagonal cordierite as the principal crystalline phase at ≤970°C sintering temp. in a relatively broad sintering temp. range.

CONSTITUTION: This glass powder has the compsn., by mol on an oxide basis, of 48-61% SiO2, 10-16% Al2O3, 23-35% MgO, 0-4% B2O3, 0-2.5% P2O5, 0.5-5% ΣB2O3+P2O5, 0-3% ZnO, 0-3% CaO, 0-1.5% BaO and 0.5-12% F as a substitute for O. The glass powder may contain ≤3 mol.%, in total, of one or more of the oxides PbO, SrO and SnO2. The sintering conditions can be varied within relatively broad limits without any average effect on the product obtd.