SCHOTT® ZERODUR® Glass-Ceramic

SCHOTT® ZERODUR® is a low-expansion glass-ceramic material used for precision optical, metrology, semiconductor and scientific applications where dimensional stability is critical. Its near-zero coefficient of thermal expansion, high 3D homogeneity and low internal defect level make it suitable for mirror substrates, reference components, precision positioning parts and stable structural elements used under changing temperature conditions.

We process ZERODUR® glass-ceramic according to drawings, dimensions, flatness, surface quality and application requirements. Typical processing can include cutting, grinding, polishing, drilling and precision fabrication for optical, metrology, semiconductor inspection and high-stability industrial components.

Basic Information

Item	Specification
Material Type	Low-Expansion Glass-Ceramic
Brand	SCHOTT®
Grade	ZERODUR®
Composition Type	Lithium Aluminum Silicon Oxide Glass-Ceramic
Appearance	Slightly Transparent to Amber / Yellowish Glass-Ceramic
Density	≈ 2.53 g/cm³

Thermal Properties

Item	Specification
CTE Class	Near-Zero Expansion Classes Available
CTE Range 0–50°C	Down to 0 ± 0.007 ppm/K depending on grade
Typical CTE 20–300°C	≈ 0.05 × 10⁻⁶ /K
Maximum Application Temperature	≈ 600°C
Thermal Conductivity	≈ 1.46 W/(m·K)
Specific Heat Capacity	≈ 0.82 J/(g·K)

SCHOTT’s official technical data separates ZERODUR® into multiple CTE tolerance classes, including 0 ± 0.100 ppm/K, 0 ± 0.050 ppm/K, 0 ± 0.020 ppm/K and tighter classes for demanding applications.

Dimensional Stability

Item	Specification
Thermal Expansion Behavior	Extremely Low / Near-Zero
CTE Homogeneity	Excellent through the material volume
Long-Term Stability	Suitable for high-precision reference components
Bulk Stress	Low, depending on blank specification
Internal Quality	Low inclusions, striae and defects
Temperature Sensitivity	Low dimensional change under temperature variation

Mechanical Properties

Item	Specification
Young’s Modulus	≈ 90.3 GPa
Poisson’s Ratio	≈ 0.24
Knoop Hardness	≈ 620 HK
Density	≈ 2.53 g/cm³
Fracture Behavior	Similar to precision glass-ceramic materials
Processing Method	Diamond grinding, polishing and precision machining

Optical & Surface Properties

Item	Specification
Optical Use	Mainly mirror substrate and precision reference use
Visible Appearance	Slightly transparent / amber tone
Surface Finish Capability	Can be ground and polished
Polishability	Suitable for high-precision optical surfaces
Coating Compatibility	Suitable for optical coating substrates
Typical Surface Requirement	Flatness, roughness and figure accuracy by drawing

SCHOTT notes that ZERODUR® can be processed into customized shapes, polished to very smooth surfaces, and used as a substrate for high-tech coatings.

Chemical & Material Stability

Item	Specification
Chemical Stability	Good
Porosity	Non-porous
Helium Permeability	Low
Moisture Resistance	Good for stable optical and metrology parts
HF Resistance	Poor, attacked by HF
Cleaning Compatibility	Suitable for controlled optical cleaning processes

Typical Applications

Field	Application
Astronomy	Telescope mirror substrates and precision optical mirrors
Precision Metrology	Reference plates, metrology bases and calibration components
Semiconductor	Inspection stages, lithography-related support parts and stable optical structures
Laser Systems	Stable mirror substrates and optical reference components
Aerospace & Scientific Instruments	Dimensionally stable structural and optical parts
Industrial Precision Equipment	Low-expansion positioning parts and high-stability platforms

ZERODUR® is widely associated with ultra-precise mirror substrates in astronomy and other applications where geometric stability under temperature variation is important.

Custom Processing Options

Processing Requirement	Available Options
Shape Processing	Custom plates, discs, blocks and shaped parts
Cutting	Drawing-based cutting and sizing
Grinding	Edge grinding, surface grinding and thickness control
Polishing	Optical or precision surface polishing by requirement
Drilling / Machining	Holes, slots and CNC features depending on design
Surface Requirement	Flatness, parallelism, roughness and coating preparation
Inspection	Dimensional and surface quality inspection according to order requirements

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Send us your ZERODUR® glass-ceramic requirements, including material grade, size, thickness, drawing, surface quality, flatness, quantity and application conditions. We can review the processing feasibility and provide a custom quotation based on your precision part requirements.