Fine Cordierite® Low Thermal Expansion Mirror
By employing Fine Cordierite in low thermal expansion mirrors, the following advantages can be expected:
- Dense cordierite with a low coefficient of thermal expansion that reduces deformation from temperature changes.
- By thinning and lightweighting, Fine Cordierite is approximately 1/2 in weight compared to low thermal expansion glass. *Kyocera estimate
- With high stiffness, cordierite can also be used as a structural component. Kyocera’s Fine Cordierite enables athermal (high temperature stability) optics in a monolithic combination of mirror and structural design.
- Achieves high manufacturing efficiency even for complex shapes due to excellent machinability and shortens production times.
- Property :
- High Stiffness
- Low Thermal Expansion
Product Data
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Material |
*High-performance cordierite developed by Kyocera for astronomy and space applications is marketed under the trademark Fine Cordierite. |
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| Special Process |
Lightweighting is possible through a rib structure. |
*In addition to ceramic components, we also offer precision polishing and mirror processing based on customer requests. Please feel free to contact us.
*Fine Cordierite is a registered trademark of Kyocera Corporation in Japan and the EU.
Features
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Fine Cordierite is a low thermal expansion material,especially at room temperature. |
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Fine Cordierite has a higher Young's modulus compared to low thermal expansion glass. Therefore, it reduces deflection due to its own weight. |
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Fine Cordierite is lightweight, yet also has a high Young's modulus. |
Furthermore, Fine Cordierite offers high stiffness, thinning, and complex rib shape processing to enable lightweighting by approximately 1/3 compared to low thermal expansion glass. *Kyocera estimate
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Fine Cordierite has high dimensional stability even with long-term use. |
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Fine Cordierite has higher thermal conductivity compared to low thermal expansion glass. |
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Fine Cordierite is a lightweight, high-strength, and thermally stable material. |
・Vertical Axis：Specific Stiffness
Height of Young's modulus relative to density. A higher value indicates high stiffness despite being lightweight.
・Horizontal Axis：Thermal Stability
Value obtained by dividing thermal conductivity by linear thermal expansion coefficient. A higher value indicates resistance to expansion as well as rapid and uniform heat distribution.
Mirror Specifications
Processing Capability
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Spape Options ✓ Flat Surface ✓ Spherical Surface ✓ Aspherical Surface ＋ We also accept consultations for other custom shapes. |
Coating Options ✓ Aluminum ✓ Gold ✓ Silver ✓ Enhanced Reflectance Film ＋ We also accept consultations for special coatings. |
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Available Sizes
Kyocera has a track record of manufacturing large products exceeding Φ1000 mm.
Furthermore, since the entire unit can be manufactured from cordierite material, athermal design that is robust against thermal changes in the ambient environment is possible.
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Dia.1.3m(Dia. after sintering) |
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Surface Roughness / Flatness
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Material Characteristics Table
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Fine Cordierite (CO720O/Kyocera) |
Low Thermal Expansion Glass |
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| Density |
g/cm³ |
2.54 |
2.53 |
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Thermal Expansion Coefficient* |
ppb/K |
0 ＋/- 20 |
0 ＋/- 20 |
| Young's Modulus |
GPa |
145 |
90 |
| Specific Rigidity |
GPa/ (g/cm³) |
57 |
36 |
| Thermal Conductivity |
W/m・K |
4 |
1.5 |
＊CO720O at 22℃ Low Thermal Expansion Glass 0℃～50℃
The values on this page are reference values based on test piece measurements, and characteristic values may vary depending on product shape and usage conditions (according to Kyocera research).
Numerical values for materials other than Fine Cordierite refer to publicly available catalog data from each company.
Applications
- Telescope Mirrors
- Mirrors for Semiconductor Manufacturing Equipment
- Mirrors for 3D Measuring Machines
