Machinable Glass Ceramic Sheets are advanced engineered materials combining properties of glass and ceramics. Formed through controlled crystallization of specific glass compositions (often involving fluorophlogopite mica or lithium silicate), they offer the unique ability to be precision-machined using conventional metalworking tools (carbide or HSS drills, mills, lathes). This eliminates the need for expensive diamond grinding typically required for traditional ceramics. They are ideal for creating complex, high-tolerance components for demanding environments.

Key Advantages

• Exceptional Machinability: Core advantage - can be drilled, tapped, threaded, milled, turned, and sawn to tight tolerances (±0.01 mm achievable).

• High-Temperature Stability: Continuous service typically up to 800°C - 1100°C (1472°F - 2012°F), depending on specific composition.

• Superior Electrical Insulation: Excellent dielectric properties, even at elevated temperatures.

• Ultra-Low Outgassing: Exceptional vacuum compatibility (low TML & CVCM), critical for UHV applications.

• Controlled Thermal Expansion: Can be tailored to match metals (e.g., steel, Kovar) for reliable seals.

• Excellent Chemical Resistance: Resists most acids, alkalis, solvents, and molten metals (except HF and strong phosphoric acid).

• Non-Porous & Hermetic: Zero water absorption, inherently vacuum-tight.

• Thermal & Electrical Insulator: Low thermal conductivity and high electrical resistivity.

• Non-Magnetic & Non-Sparking.

• Flame Retardant & Non-Combustible.

• Good Dimensional Stability.

Performance Characteristics (Typical Range - Varies by Grade)

• Max. Continuous Operating Temp: 700°C - 1100°C (1292°F - 2012°F) - Depends on composition (e.g., mica-based vs. lithium-based).

• Thermal Expansion Coefficient (CTE): 7 - 12 x 10⁻⁶/°C (25-300°C) - Often designed to match metals.

• Thermal Conductivity: 1.2 - 2.0 W/m·K.

• Dielectric Strength: 20 - 40 kV/mm.

• Volume Resistivity: >10¹² - 10¹⁴ Ω·cm @ 500°C.

• Dielectric Constant (1 MHz): 5.5 - 7.5.

• Dissipation Factor (1 MHz): 0.001 - 0.01.

• Density: 2.4 - 2.7 g/cm³.

• Flexural Strength: 70 - 150 MPa (10,000 - 22,000 psi).

• Compressive Strength: 300 - 500 MPa (44,000 - 73,000 psi).

• Hardness: Knoop 200 - 350 (softer than alumina/zirconia, enabling machinability).

• Water Absorption: 0%.

• Outgassing (ASTM E595): TML < 0.80%, CVCM < 0.10% (typical for high grades).

Primary Applications

• Semiconductor Manufacturing: Precision fixtures, plasma etch components, insulators, heater blocks, shadow frames, wafer chucks.

• Aerospace & Defense: Radomes, antenna windows, thermal barriers, sensor housings, vacuum feedthroughs, microwave components.

• Vacuum & Thin Film Technology (UHV): Flanges, sputtering targets, PVD/CVD fixtures, sample holders, viewports.

• High-Temperature Instrumentation: Thermocouple insulators, furnace sight tubes, sensor mounts, burner plates, thermowell liners.

• Electrical & RF Engineering: High-voltage insulators, coil bobbins, microwave windows, waveguide components, switchgear.

• Laser & Optical Systems: Stable optical mounts, mirror substrates, laser cavity spacers, Faraday isolator bases.

• Medical Equipment: MRI components, X-ray tube parts, sterilizable surgical tooling, non-magnetic fixtures.

• Research & Laboratory: Custom experimental fixtures, sample holders, insulating spacers, non-contaminating surfaces.

• Glass-to-Metal & Ceramic-to-Metal Seals: Utilizing matched CTE.

• Prototyping & Low-Volume Production: Rapidly machined complex parts for testing or end-use in harsh environments.