ULE 7972 PREM
Grade
also Corning 7972
PREM = premium / Class 1 Grade
Choose for EUV mask blanks, metrology standards and diffraction-limited optics where CTE uniformity dominates.
Values for the PREM condition
What is ULE 7972 PREM?
ULE 7972 PREM is ULE 7972 in the PREM grade — choose for EUV mask blanks, metrology standards and diffraction-limited optics where CTE uniformity dominates. ULE 7972 PREM has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. The elastic modulus is 67.6 GPa (9.8 Msi). ULE 7972 PREM has a density of 2.21 g/cm³ (0.0798 lb/in³), lighter than 88% of glass grades.
Advantages
- Lightweight — 2.21 g/cm³ (0.0798 lb/in³), better than 88% of glass grades
- High service temperature — 890°C (1,634 °F), better than 83% of glass grades
- Good corrosion resistance — 92/100, better than 81% of glass grades
ULE 7972 PREM properties
Typical room-temperature values for ULE 7972 PREM; 3 are specific to this condition. Other listed values are ULE 7972 reference data and may not represent this condition. Bars are the position among glass grades.
Physical4
ULE 7972 PREM has a density of 2.21 g/cm³ (0.0798 lb/in³), lighter than 88% of glass grades.
Mechanical11
ULE 7972 PREM has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. The elastic modulus is 67.6 GPa (9.8 Msi).
Thermal5
ULE 7972 PREM is rated for continuous service to 890°C (1,634 °F). It conducts heat at 1.3 W/m·K (0.757 BTU/hr·ft·°F), worse than 51% of glass grades. Thermal expansion is 0 µm/m·K (0 µin/in·°F).
Electrical5
ULE 7972 PREM is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (92/100), better than 81% of glass grades.
Sustainability4
Producing a kilogram of ULE 7972 PREM takes about 200 MJ of energy and emits 14 kg of CO₂ — more than 71% of glass grades. Typical recycled content is 0%.
Manufacturability2
ULE 7972 PREM's machinability is poor (15/100, worse than 54% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ULE 7972 PREM
Is ULE 7972 easy to machine?
Diamond grinding, core drilling and ultrasonic/abrasive-waterjet machining only; deep pocket lightweighting to >80 % mass removal is routine but slow and chip-out prone at edges.
Can ULE 7972 be welded?
Joined by low-temperature frit bonding, hydroxide-catalysis bonding or high-temperature fusion sealing of ULE-to-ULE; never metal-welded, and thermal joining requires careful re-annealing to preserve CTE uniformity.
Can ULE 7972 be formed, bent or molded?
Supplied as flame-hydrolysis boules that are sliced and slumped/fused near 1500 °C; slumping and any hot work must be followed by controlled annealing around 1000 °C.
What surface finishes work on ULE 7972?
Polishes to sub-nanometre rms with cerium oxide and ion-beam figuring; optical coatings (Mo/Si multilayer, Al+MgF₂) adhere well, and acid etching with HF is used only for subsurface-damage removal.
ULE 7972 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| TiO2titania dopant sets the zero-crossing temperature of CTE | 6.5 – 9 | 7.5 |
| OHresidual hydroxyl from the flame process | 0 – 0.12 | 0.08 |
| SiO2synthetic silica from flame hydrolysis | ≥ 91 (balance) |
ULE 7972 PREM — frequently asked
What is ULE 7972 PREM used for?
ULE 7972 PREM is typically used for telescope mirror blanks, EUV lithography optics and metrology standards. In short: near-zero CTE substrate; lightweightable mirror blank; zerodur-class stability.
What is the tensile strength of ULE 7972 PREM?
ULE 7972 PREM has a typical tensile strength of 50 MPa (7.25 ksi) — stronger than 59% of glass grades.
Is ULE 7972 PREM easy to machine?
Not especially — machinability is rated poor (15/100, worse than 54% of glass grades). Diamond grinding, core drilling and ultrasonic/abrasive-waterjet machining only; deep pocket lightweighting to >80 % mass removal is routine but slow and chip-out prone at edges.
Can ULE 7972 PREM be welded?
Joined by low-temperature frit bonding, hydroxide-catalysis bonding or high-temperature fusion sealing of ULE-to-ULE; never metal-welded, and thermal joining requires careful re-annealing to preserve CTE uniformity.
What surface finishes work on ULE 7972 PREM?
Polishes to sub-nanometre rms with cerium oxide and ion-beam figuring; optical coatings (Mo/Si multilayer, Al+MgF₂) adhere well, and acid etching with HF is used only for subsurface-damage removal.
Can ULE 7972 PREM be formed, bent or molded?
Supplied as flame-hydrolysis boules that are sliced and slumped/fused near 1500 °C; slumping and any hot work must be followed by controlled annealing around 1000 °C.
What is the maximum service temperature of ULE 7972 PREM?
ULE 7972 PREM is rated for continuous use to about 890°C (1,634 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ULE Corning Code 7972 Ultra Low Expansion Glass — Product Information — Corning Incorporated (Specialty Materials) (2016)
- Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Properties of low-expansion optical substrate materials (ULE vs Zerodur vs fused silica) — SPIE Proceedings compilations (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.