Graphite Felt RGF-HP
Grade
RGF-HP = rayon (viscose)-based, halogen-purified high-purity graphite felt
Use in single-crystal silicon, sapphire and semiconductor furnaces where ash/metal contamination and out-gassing must be minimal.
Values for the RGF-HP condition
Other Graphite Felt tempers and conditions
Graphite Felt is listed in 4 conditions; see the grade overview at Graphite Felt.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
RGF-HPThis page Rayon (viscose)-based, halogen-purified high-purity graphite felt | Use in single-crystal silicon, sapphire and semiconductor furnaces where ash/metal contamination and out-gassing must be minimal. | — | 0.2 | 12 | — | 0.08 W/m·K |
SGFDefault Soft graphite felt, PAN-based, needled | Default flexible insulation blanket/roll for vacuum and inert-gas hot zones; cheapest and easiest to wrap around cylindrical chambers. | — | 0.3 | 10 | — | 0.09 W/m·K |
Carbon felt, carbonised only | Lower-cost, higher-resistivity felt for service below ~1600 °C and for redox-flow-battery / filtration electrodes. | — | 0.4 | 8 | — | 0.08 W/m·K |
Rigid graphite felt board | Pick when the insulation must be self-supporting, machinable to shape, or must resist gas erosion in a vacuum furnace hot zone. | — | 0.8 | — | — | 0.2 W/m·K |
What is Graphite Felt RGF-HP?
Graphite Felt RGF-HP is Graphite Felt in the RGF-HP grade — use in single-crystal silicon, sapphire and semiconductor furnaces where ash/metal contamination and out-gassing must be minimal. Graphite Felt RGF-HP has a tensile strength of 0.2 MPa (0.029 ksi), weaker than 99% of ceramic grades. Elongation at break is 12% and the elastic modulus is 0 GPa (2.9×10⁻⁴ Msi). Graphite Felt RGF-HP has a density of 0.09 g/cm³ (0.0033 lb/in³), lighter than 99% of ceramic grades. It melts at 3,650°C (6,602 °F). SGF is the default condition FabDigit quotes; RGF-HP is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 12%, better than 101% of ceramic grades
- Lightweight — 0.09 g/cm³ (0.0033 lb/in³), better than 99% of ceramic grades
- Easy to machine — 95/100, better than 99% of ceramic grades
- High service temperature — 2,500°C (4,532 °F), better than 98% of ceramic grades
Limitations
- Low stiffness — 0 GPa (2.9×10⁻⁴ Msi), worse than 100% of ceramic grades
- Poor heat conductor — 0.08 W/m·K (0.0462 BTU/hr·ft·°F), worse than 99% of ceramic grades
- High embodied carbon — 25 kg CO₂/kg, worse than 78% of ceramic grades
Graphite Felt RGF-HP properties
Typical room-temperature values for Graphite Felt RGF-HP; 12 are specific to this condition. Other listed values are Graphite Felt reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
Graphite Felt RGF-HP has a density of 0.09 g/cm³ (0.0033 lb/in³), lighter than 99% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical6
Graphite Felt RGF-HP has a tensile strength of 0.2 MPa (0.029 ksi), weaker than 99% of ceramic grades. Elongation at break is 12% and the elastic modulus is 0 GPa (2.9×10⁻⁴ Msi).
Thermal4
Graphite Felt RGF-HP is rated for continuous service to 2,500°C (4,532 °F). It conducts heat at 0.08 W/m·K (0.0462 BTU/hr·ft·°F), worse than 99% of ceramic grades.
Electrical2
Graphite Felt RGF-HP has an electrical resistivity of 0.004 Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (80/100), better than 56% of ceramic grades.
Sustainability3
Producing a kilogram of Graphite Felt RGF-HP takes about 300 MJ of energy and emits 25 kg of CO₂ — more than 74% of ceramic grades. Typical recycled content is 5%.
Manufacturability2
Graphite Felt RGF-HP's machinability is excellent (95/100, better than 99% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Graphite Felt RGF-HP
Is Graphite Felt easy to machine?
Soft felt is cut with a razor blade, die or waterjet; rigid board is sawn/milled dry with carbide tools — always use HEPA dust extraction and avoid coolant absorption.
Can Graphite Felt be welded?
Not weldable; joined mechanically with graphite pins, CFC screws, graphite foil clamps or carbonising cement.
Can Graphite Felt be formed, bent or molded?
Supplied as needled roll or press-moulded rigid board; soft felt drapes and wraps to small radii and can be layered/compressed to tune conductivity.
What surface finishes work on Graphite Felt?
Optionally faced with graphite foil, CFC skin or SiC/pyrocarbon CVD coating to stop erosion and dusting; halogen purification at ~2000 °C removes metallic ash.
Graphite Felt 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 |
|---|---|---|
| ash≤500 ppm standard; ≤50 ppm for halogen-purified high-purity grade | 0.01 – 0.5 | 0.05 |
| Nresidual nitrogen in PAN-based, carbonised (non-graphitised) felt only | ≤ 0.5 | 0.2 |
| Cgraphitised carbon fibre; purified grades ≥99.99 % | ≥ 99 (balance) | — |
Graphite Felt RGF-HP — frequently asked
What is Graphite Felt RGF-HP used for?
Graphite Felt RGF-HP is typically used for furnace hot-zone insulation, crystal-growth furnace lining and electrode felt for redox-flow batteries. In short: lowest-conductivity graphite insulation; 2200 °C in inert atmosphere; no load-bearing capability.
What is the tensile strength of Graphite Felt RGF-HP?
Graphite Felt RGF-HP has a typical tensile strength of 0.2 MPa (0.029 ksi) — weaker than 99% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is Graphite Felt RGF-HP easy to machine?
Yes — machinability is rated excellent (95/100, better than 99% of ceramic grades). Soft felt is cut with a razor blade, die or waterjet; rigid board is sawn/milled dry with carbide tools — always use HEPA dust extraction and avoid coolant absorption.
Can Graphite Felt RGF-HP be welded?
Not weldable; joined mechanically with graphite pins, CFC screws, graphite foil clamps or carbonising cement.
What surface finishes work on Graphite Felt RGF-HP?
Optionally faced with graphite foil, CFC skin or SiC/pyrocarbon CVD coating to stop erosion and dusting; halogen purification at ~2000 °C removes metallic ash.
Can Graphite Felt RGF-HP be formed, bent or molded?
Supplied as needled roll or press-moulded rigid board; soft felt drapes and wraps to small radii and can be layered/compressed to tune conductivity.
What is the maximum service temperature of Graphite Felt RGF-HP?
Graphite Felt RGF-HP is rated for continuous use to about 2,500°C (4,532 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- SIGRATHERM soft and rigid graphite felt insulation data sheets — SGL Carbon (2022)
- Carbon and graphite felt / rigid board hot-zone insulation — Kureha / Mersen (2021)
- ASM Handbook Vol. 4 — Heat Treating (furnace insulation materials) — ASM International (1991)
- GB/T 32545 / (industry practice) — SAC (2016)
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.