AgBr SC-OPT
Grade · default condition
SC-OPT = optical-grade single crystal
Choose for windows, ATR prisms and lenses where lowest scatter and best IR transmission are needed.
Values for the SC-OPT condition
Other AgBr tempers and conditions
AgBr is listed in 3 conditions; see the grade overview at AgBr.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SC-OPTDefaultThis page Optical-grade single crystal | Choose for windows, ATR prisms and lenses where lowest scatter and best IR transmission are needed. | — | 20 | 40 | — | 1 W/m·K |
Hot-pressed / forged polycrystalline blank | Choose for large, low-cost windows and gaskets where slight scatter is acceptable. | — | 24 | 20 | 10 HV | 1 W/m·K |
Extruded polycrystalline rod / IR fiber preform | Choose when the material must be cold-extruded into unclad far-IR fibres or flexible light guides. | — | 28 | 50 | 9 HV | 1 W/m·K |
What is AgBr SC-OPT?
AgBr SC-OPT is AgBr in the SC-OPT grade — choose for windows, ATR prisms and lenses where lowest scatter and best IR transmission are needed. AgBr SC-OPT has a tensile strength of 20 MPa (2.9 ksi), weaker than 89% of glass grades. Elongation at break is 40% and the elastic modulus is 22 GPa (3.19 Msi). AgBr SC-OPT has a density of 6.47 g/cm³ (0.234 lb/in³), heavier than 98% of glass grades. It melts at 432°C (810 °F).
Advantages
- Ductile — tolerates forming and impact — 40%, better than 100% of glass grades
Limitations
- Heavy — 6.47 g/cm³ (0.234 lb/in³), worse than 98% of glass grades
- Low stiffness — 22 GPa (3.19 Msi), worse than 92% of glass grades
- High embodied carbon — 70 kg CO₂/kg, worse than 90% of glass grades
- Limited service temperature — 200°C (392 °F), worse than 88% of glass grades
- Hard to polish — 55/100, worse than 85% of glass grades
AgBr SC-OPT properties
Typical room-temperature values for AgBr SC-OPT; 10 are specific to this condition. Other listed values are AgBr reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
AgBr SC-OPT has a density of 6.47 g/cm³ (0.234 lb/in³), heavier than 98% of glass grades. It melts at 432°C (810 °F).
Mechanical11
AgBr SC-OPT has a tensile strength of 20 MPa (2.9 ksi), weaker than 89% of glass grades. Elongation at break is 40% and the elastic modulus is 22 GPa (3.19 Msi).
Thermal5
AgBr SC-OPT is rated for continuous service to 200°C (392 °F). It conducts heat at 1.1 W/m·K (0.636 BTU/hr·ft·°F), worse than 68% of glass grades. Thermal expansion is 33 µm/m·K (18.3 µin/in·°F).
Electrical3
AgBr SC-OPT has an electrical resistivity of 1,000,000 Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (72/100), worse than 53% of glass grades.
Sustainability4
Producing a kilogram of AgBr SC-OPT takes about 900 MJ of energy and emits 70 kg of CO₂ — more than 89% of glass grades. Typical recycled content is 40%.
Manufacturability2
AgBr SC-OPT's machinability is poor (30/100, better than 71% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AgBr SC-OPT
Is AgBr easy to machine?
Very soft and prone to smearing on the tool — use single-point diamond turning or light-load diamond sawing. Cutting fluids must be free of ammonia and sulfides, and aluminium or copper fixtures must not be used.
Can AgBr be welded?
Not weldable; components are cold-welded by press or extrusion plastic deformation, or bonded with optical cement.
Can AgBr be formed, bent or molded?
Flows plastically at room temperature, so it can be cold extruded into IR fibre or hot pressed into window blanks. Forming temperature is typically 100–250 °C, with silver-plated or graphite dies.
What surface finishes work on AgBr?
Wet polish with very fine diamond slurry in anhydrous or neutral media. Store polished parts away from light; AR coating is normally applied to offset the high reflection loss from n≈2.25.
AgBr 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 |
|---|---|---|
| Agstoichiometric AgBr, M = 187.77 g/mol | 57.2 – 57.7 | 57.45 |
| impuritiestypical 4N–5N raw salt; Cl, I, Fe, Cu, Pb controlled at ppm level | ≤ 0.05 | 0.01 |
| Br | ≥ 42.3 (balance) | — |
AgBr SC-OPT — frequently asked
What is AgBr SC-OPT used for?
AgBr SC-OPT is typically used for far-IR fiber optics, IR windows in humid/marine settings and radiometry components. In short: transmits to 35 µm; non-hygroscopic silver halide; cold-extrudable into fibre.
What is the tensile strength of AgBr SC-OPT?
AgBr SC-OPT has a typical tensile strength of 20 MPa (2.9 ksi) — weaker than 89% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is AgBr SC-OPT easy to machine?
Not especially — machinability is rated poor (30/100, better than 71% of glass grades). Very soft and prone to smearing on the tool — use single-point diamond turning or light-load diamond sawing. Cutting fluids must be free of ammonia and sulfides, and aluminium or copper fixtures must not be used.
Can AgBr SC-OPT be welded?
Not weldable; components are cold-welded by press or extrusion plastic deformation, or bonded with optical cement.
What surface finishes work on AgBr SC-OPT?
Wet polish with very fine diamond slurry in anhydrous or neutral media. Store polished parts away from light; AR coating is normally applied to offset the high reflection loss from n≈2.25.
Can AgBr SC-OPT be formed, bent or molded?
Flows plastically at room temperature, so it can be cold extruded into IR fibre or hot pressed into window blanks. Forming temperature is typically 100–250 °C, with silver-plated or graphite dies.
What is the maximum service temperature of AgBr SC-OPT?
AgBr SC-OPT is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- CRC Handbook of Chemistry and Physics — silver bromide physical data — CRC Press (2021)
- Handbook of Optical Constants of Solids (Palik) — AgBr — Academic Press (1998)
- Infrared window & ATR crystal material property tables (silver halides) — IR optics manufacturers (2023)
- Elastic constants of alkali/silver halides — Landolt-Börnstein (1992)
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.