Mica

Muscovite mica (KAl₂(AlSi₃O₁₀)(OH)₂) is the most common type, suitable for most electrical ceramic applications up to ~700°C. Phlogopite mica (KMg₃(AlSi₃O₁₀)(OH)₂) is thermally superior, stable to ~1000°C, making it preferred for high-temperature electrical and refractory ceramic applications.

Mica's plate-like (lamellar) structure provides anisotropic reinforcement within the ceramic body — the layers resist crack propagation perpendicular to the plates. This improves the mechanical strength of the ceramic matrix, particularly resistance to delamination and impact fracture in electrical insulator applications.

Yes. The presence of mica significantly improves the dielectric breakdown strength of electrical porcelain ceramics. The layered structure creates multiple high-resistance barriers to electrical discharge, effectively improving the insulation resistance of the ceramic body under high-voltage conditions.

Mica is most critical in high-voltage power line insulators, surge arresters, spark plug ceramics, and high-frequency electrical porcelain where dielectric strength and electrical insulation performance under thermal and electrical stress are primary design requirements.

Yes. Mica is typically used in combination with kaolin, feldspar, silica, and alumina in electrical ceramic body formulations. The proportion of mica is carefully controlled to balance the electrical insulation benefits with the firing behaviour and mechanical properties required for the specific insulator design.