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Nuclear Graphite IG-110

Grade · default condition

ASTM D7219

IG-110 = isostatically molded superfine-grain isotropic nuclear graphite

Default choice for HTGR/HTR-PM fuel blocks, reflectors and molten-salt reactor components where fine grain (~20 µm), high isotropy and proven irradiation database matter.

High cost $$$$

Values for the IG-110 condition

Other Nuclear Graphite tempers and conditions

Nuclear Graphite is listed in 4 conditions; see the grade overview at Nuclear Graphite.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Extruded medium-grain petroleum-coke nuclear graphite
Use where large extruded sections and cost matter and mild property anisotropy (with-grain vs against-grain) is acceptable; strength is lower than isostatic grades.—17——140 W/m·K
Vibration-molded medium-grain pitch-coke near-isotropic nuclear graphite
Choose for large pebble-bed reflector blocks where big billet sizes, high thermal conductivity and low irradiation-induced dimensional change dominate over fine grain size.—22——150 W/m·K
IG-110DefaultThis page
Isostatically molded superfine-grain isotropic nuclear graphite
Default choice for HTGR/HTR-PM fuel blocks, reflectors and molten-salt reactor components where fine grain (~20 µm), high isotropy and proven irradiation database matter.—25——120 W/m·K
High-density isostatic fine-grain nuclear graphite
Pick when higher strength and density than IG-110 are needed for control-rod sleeves, high-stress reflector parts or MSR components.—37——140 W/m·K

What is Nuclear Graphite IG-110?

Nuclear Graphite IG-110 is Nuclear Graphite in the IG-110 grade — default choice for HTGR/HTR-PM fuel blocks, reflectors and molten-salt reactor components where fine grain (~20 µm), high isotropy and proven irradiation database matter. Nuclear Graphite IG-110 has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. The elastic modulus is 9.8 GPa (1.42 Msi). Nuclear Graphite IG-110 has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 90% of ceramic grades. It melts at 3,650°C (6,602 °F).

Advantages

  • High service temperature — 2,500°C (4,532 °F), better than 98% of ceramic grades
  • Easy to machine — 93/100, better than 98% of ceramic grades
  • Lightweight — 1.78 g/cm³ (0.0643 lb/in³), better than 90% of ceramic grades
  • Conducts heat well — 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades

Limitations

  • Low fracture toughness — 0.9 MPa·√m (0.819 ksi·√in), worse than 96% of ceramic grades
  • Low stiffness — 9.8 GPa (1.42 Msi), worse than 94% of ceramic grades
  • Hard to polish — 35/100, worse than 93% of ceramic grades

Nuclear Graphite IG-110 properties

Typical room-temperature values for Nuclear Graphite IG-110; 13 are specific to this condition. Other listed values are Nuclear Graphite reference data and may not represent this condition. Bars are the position among ceramic grades.

Physical3

Nuclear Graphite IG-110 has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 90% of ceramic grades. It melts at 3,650°C (6,602 °F).

Density1.78 g/cm³0.06 lb/in³
Melting Point (Solidus)3,650°C6,602 °F
Porosity20%

Mechanical10

Nuclear Graphite IG-110 has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. The elastic modulus is 9.8 GPa (1.42 Msi).

Elastic (Young's) Modulus9.8 GPa1.4 Msi
Shear Modulus4.4 GPa0.64 Msi
Bulk Modulus5 GPa0.67 Msi
Poisson's Ratio0.14
Tensile Strength (Ultimate)25 MPa3.6 ksi
Compressive Strength78 MPa11.3 ksi
Flexural Strength39 MPa5.7 ksi
Shear Strength22 MPa3.2 ksi
Fracture Toughness (K_IC)0.9 MPa·√m0.82 ksi·√in
Hardness, Mohs1.5

Thermal5

Nuclear Graphite IG-110 is rated for continuous service to 2,500°C (4,532 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).

Thermal Conductivity120 W/m·K69.3 BTU/hr·ft·°F
Specific Heat Capacity710 J/kg·K0.17 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)4.5 µm/m·K2.5 µin/in·°F
Max Service Temperature (continuous)2,500°C4,532 °F
Min Service Temperature-200°C-328 °F

Electrical2

Nuclear Graphite IG-110 has an electrical resistivity of 1.1×10⁻⁵ Ω·m.

Electrical Resistivity1.1×10⁻⁵ Ω·m433 µΩ·in
Volume Resistivity0 Ω·cm

Chemical & Environmental2

Corrosion resistance is very good (75/100), better than 50% of ceramic grades.

Corrosion ResistanceVery good75/100
Chemical Resistance SummaryInert to nearly all acids, alkalis, organic solvents and molten fluoride salts; attacked by strong oxidizers (nitric acid, chromic acid), oxidizes in air/CO2/steam above ~400–600 °C, and reacts with molten alkali metals and carbide-forming metals at high temperature.

Sustainability4

Producing a kilogram of Nuclear Graphite IG-110 takes about 180 MJ of energy and emits 14 kg of CO₂ — more than 60% of ceramic grades. Typical recycled content is 0%.

Embodied Energy (primary production)180 MJ/kg77,386 BTU/lb
Embodied Carbon (primary production)14 kg CO₂/kg
Embodied Water60 L/kg7.2 gal/lb
Typical Recycled Content0%

Manufacturability3

Nuclear Graphite IG-110's machinability is excellent (93/100, better than 98% of ceramic grades).

MachinabilityExcellent93/100
PolishabilityFair35/100
Sintering / Firing Temperature2,900°C5,252 °F

Common Calculations4

Specific Strength (UTS / density)calculated14 kN·m/kg
Specific Stiffness (E / density)calculated5.5 MN·m/kg
Thermal Diffusivitycalculated95 mm²/s
Thermal Shock Resistance Indexcalculated68

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Nuclear Graphite IG-110

Is Nuclear Graphite easy to machine?

Machines dry very easily with carbide or PCD tooling at high speed, but the dust is abrasive, electrically conductive and must be vacuum-extracted; avoid cutting fluids that contaminate the pores.

Can Nuclear Graphite be welded?

Not weldable — parts are joined mechanically (threaded keys, dowels, graphite bolts) or with carbonaceous cements that are carbonized/graphitized after assembly.

Can Nuclear Graphite be formed, bent or molded?

Formed only at the green stage by isostatic pressing, vibration molding or extrusion of coke/pitch mix, then baked, pitch-impregnated, graphitized >2800 °C and halogen-purified; finished blocks are shaped only by machining.

What surface finishes work on Nuclear Graphite?

Surfaces are typically machined and cleaned by baking/vacuum outgassing; optional SiC or pyrolytic-carbon CVD coatings or phosphate-based antioxidants improve oxidation resistance above 500 °C.

Nuclear Graphite 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.

ElementSpec limit (wt %)Nominal
ashtotal ash, typically <20–300 ppm depending on grade≤ 0.030
Bboron equivalent typically ≤2 ppm per ASTM D7219≤ 2×10⁻⁴5×10⁻⁵
Vresidual from petroleum coke≤ 5×10⁻⁴1×10⁻⁴
Fe≤ 02×10⁻⁴
S≤ 0.010
Cafter halogen purification≥ 99.95 (balance)—

Nuclear Graphite IG-110 — frequently asked

What is Nuclear Graphite IG-110 used for?

Nuclear Graphite IG-110 is typically used for reactor moderator blocks, reflector components, fuel element sleeves and HTGR structural parts. In short: nuclear-qualified isotropic graphite; low boron, high purity; brittle, low tensile strength.

What is the tensile strength of Nuclear Graphite IG-110?

Nuclear Graphite IG-110 has a typical tensile strength of 25 MPa (3.63 ksi) — weaker than 85% of ceramic grades. Strength varies by condition: see the 4 listed tempers.

Is Nuclear Graphite IG-110 easy to machine?

Yes — machinability is rated excellent (93/100, better than 98% of ceramic grades). Machines dry very easily with carbide or PCD tooling at high speed, but the dust is abrasive, electrically conductive and must be vacuum-extracted; avoid cutting fluids that contaminate the pores.

Can Nuclear Graphite IG-110 be welded?

Not weldable — parts are joined mechanically (threaded keys, dowels, graphite bolts) or with carbonaceous cements that are carbonized/graphitized after assembly.

What surface finishes work on Nuclear Graphite IG-110?

Surfaces are typically machined and cleaned by baking/vacuum outgassing; optional SiC or pyrolytic-carbon CVD coatings or phosphate-based antioxidants improve oxidation resistance above 500 °C.

Can Nuclear Graphite IG-110 be formed, bent or molded?

Formed only at the green stage by isostatic pressing, vibration molding or extrusion of coke/pitch mix, then baked, pitch-impregnated, graphitized >2800 °C and halogen-purified; finished blocks are shaped only by machining.

What is the maximum service temperature of Nuclear Graphite IG-110?

Nuclear Graphite IG-110 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

  1. ASTM D7219 — Standard Specification for Isotropic and Near-isotropic Nuclear Graphites — ASTM International (2019)
  2. ASTM D7301 — Standard Specification for Nuclear Graphite Suitable for Components Subjected to Low Neutron Irradiation Dose — ASTM International (2018)
  3. Isotropic Graphite IG-110 / IG-430 technical data — Toyo Tanso (2020)
  4. NBG-18 nuclear graphite grade data — SGL Carbon (2019)
  5. Graphite Design Handbook / NGNP Graphite Testing and Qualification (INL/EXT reports) — Idaho National Laboratory (2011)
  6. IAEA-TECDOC-1154: Irradiation Damage in Graphite due to Fast Neutrons in Fission and Fusion Systems — IAEA (2000)

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.