Ox/Ox
also Nextel/Al2O3, WHIPOX
An all-oxide CMC (typically Nextel alumina/mullite fiber in an alumina or aluminosilicate matrix) that avoids oxidation degradation, offering long-term stability at moderate temperatures (~1000-1200°C) without protective coatings.
Reference datasheet — Ox/Ox is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the N720-A condition
Ox/Ox grades and fills
Ox/Ox is supplied in 6 conditions, soft to hard. N720-A is the default FabDigit quotes; the values on this page are for it.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Wound highly porous oxide CMC | Filament-wound tubes/liners with very high matrix porosity — lightweight, extremely thermal-shock tolerant and quasi-ductile, but low strength and strongly anisotropic. | 130 | 0.5 | ||
Polymer-derived (siloxane) matrix oxide CMC, Nextel 610/720 reinforced | Low-temperature-cured, low-shrinkage route for large thin-wall burner liners and heat-treatment fixtures; cheaper to make but slightly lower strength and matrix stability than slurry Ox/Ox. | 140 | 0.35 | ||
Nextel 720 fiber in porous alumina–silica matrix | Choose for maximum thermal-shock tolerance and low CTE at 1100–1200 °C where absolute strength is secondary. | 165 | 0.4 | ||
N720-ADefault Nextel 720 (mullite+alumina) fiber in porous alumina matrix | The mainstream production Ox/Ox: best creep resistance and highest use temperature of the common systems; used for exhaust nozzles, seals and hot-gas liners. | 190 | 0.3 | ||
Nextel 610 fiber in porous alumina–silica (mullite-forming) matrix | Lower-shrinkage, lower-cost matrix version of N610; good damage tolerance and dielectric behaviour for radome/duct parts up to ~1000 °C. | 250 | 0.3 | ||
Nextel 610 (α-alumina) fiber in porous alumina matrix | Pick when room- and mid-temperature strength/stiffness matter most and service stays below ~1000 °C (610 fiber creeps above that). | 290 | 0.25 |
Supply forms, finishes and certifications
Ways Ox/Ox is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FGI | Ox/Ox + FGI | Surface finish |
What is Ox/Ox?
An all-oxide CMC (typically Nextel alumina/mullite fiber in an alumina or aluminosilicate matrix) that avoids oxidation degradation, offering long-term stability at moderate temperatures (~1000-1200°C) without protective coatings. Ox/Ox has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 87% of composite grades. Ox/Ox has a tensile strength of 190 MPa (27.6 ksi), weaker than 54% of composite grades. Elongation at break is 0.3% and the elastic modulus is 75 GPa (10.9 Msi).
What is Ox/Ox used for?
- exhaust nozzle flaps
- combustor liners
- industrial furnace components
- gas turbine exhaust mixers
- high-temperature insulation panels
Advantages
- High service temperature — 1,200°C (2,192 °F), better than 94% of composite grades
- Good corrosion resistance — 92/100, better than 94% of composite grades
- Good UV / weathering resistance — 100/100, better than 93% of composite grades
Limitations
- Limited ductility — 0.3%, worse than 95% of composite grades
- High embodied carbon — 45 kg CO₂/kg, worse than 90% of composite grades
- Heavy — 2.75 g/cm³ (0.0994 lb/in³), worse than 87% of composite grades
- Difficult to machine — 15/100, worse than 84% of composite grades
- Hard to polish — 25/100, worse than 76% of composite grades
Ox/Ox properties
Typical room-temperature values for Ox/Ox-N720-A; bars are the position among composite grades.
Physical2
Ox/Ox has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 87% of composite grades.
Mechanical11
Ox/Ox has a tensile strength of 190 MPa (27.6 ksi), weaker than 54% of composite grades. Elongation at break is 0.3% and the elastic modulus is 75 GPa (10.9 Msi).
Thermal6
Ox/Ox is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 2 W/m·K (1.16 BTU/hr·ft·°F), better than 58% of composite grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical3
Ox/Ox has an electrical resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 94% of composite grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of Ox/Ox takes about 600 MJ of energy and emits 45 kg of CO₂ — more than 87% of composite grades. Typical recycled content is 0%.
Manufacturability2
Ox/Ox's machinability is poor (15/100, worse than 84% of composite grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. Ox/Ox is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Ox/Ox
Is Ox/Ox easy to machine?
Green (pre-sinter) state trims easily with carbide/router; after sintering use diamond grinding, diamond core drilling or abrasive waterjet, and avoid sharp notches and edge delamination.
Can Ox/Ox be welded?
Not weldable — joined by mechanical fastening with ceramic/superalloy bushings, ceramic adhesives or co-sintered oxide joints.
Can Ox/Ox be formed, bent or molded?
Slurry- or sol-infiltrated prepreg is hand/automated laid up, vacuum-bagged and autoclave/oven cured, then pressureless-sintered at ~1000–1200 °C; near-net shaping is essential since re-infiltration densification is limited, and filament winding is used for WHIPOX-type tubes.
Ox/Ox 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 |
|---|---|---|
| SiO2mullite-forming silica in N720 fiber and/or aluminosilicate matrix | 8 – 28 | 20 |
| Fe2O3typical Nextel 610 fiber additive/impurity | 0 – 0.5 | 0.2 |
| B2O3grain-growth inhibitor in some oxide fibers | 0 – 0.5 | 0.1 |
| fiber volume fractionvol %, 0/90 woven laminate | 35 – 50 | 42 |
| open porosityvol %, engineered matrix porosity for crack deflection | 18 – 35 | 25 |
| Al2O3α-alumina/mullite from fiber + alumina matrix | ≥ 65 (balance) |
What surface finishes work on Ox/Ox?
Surfaces can be left as-woven or given an oxide seal/engobe, FGI insulating topcoat or reflective/emissive coating; no anodizing, plating or painting is applicable.
Equivalent designations
Standards and trade names that resolve to Ox/Ox in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Nextel/Al2O3WHIPOX
How much does Ox/Ox cost?
Ox/Ox is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Ox/Ox — frequently asked
What is Ox/Ox used for?
Ox/Ox is typically used for exhaust nozzle flaps, combustor liners, industrial furnace components, gas turbine exhaust mixers and high-temperature insulation panels. In short: oxidation-stable without coating; low thermal conductivity CMC; static hot-gas structures.
What is the tensile strength of Ox/Ox?
Ox/Ox has a typical tensile strength of 190 MPa (27.6 ksi) — weaker than 54% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is Ox/Ox easy to machine?
Not especially — machinability is rated poor (15/100, worse than 84% of composite grades). Green (pre-sinter) state trims easily with carbide/router; after sintering use diamond grinding, diamond core drilling or abrasive waterjet, and avoid sharp notches and edge delamination.
Can Ox/Ox be welded?
Not weldable — joined by mechanical fastening with ceramic/superalloy bushings, ceramic adhesives or co-sintered oxide joints.
What surface finishes work on Ox/Ox?
Surfaces can be left as-woven or given an oxide seal/engobe, FGI insulating topcoat or reflective/emissive coating; no anodizing, plating or painting is applicable.
Can Ox/Ox be formed, bent or molded?
Slurry- or sol-infiltrated prepreg is hand/automated laid up, vacuum-bagged and autoclave/oven cured, then pressureless-sintered at ~1000–1200 °C; near-net shaping is essential since re-infiltration densification is limited, and filament winding is used for WHIPOX-type tubes.
What is the maximum service temperature of Ox/Ox?
Ox/Ox is rated for continuous use to about 1,200°C (2,192 °F), and briefly to 1,300°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Ox/Ox cost?
Ox/Ox is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- COI Ceramics Oxide/Oxide CMC (N610 and N720 systems) property sheets — COI Ceramics / ATK (2015)
- Nextel Ceramic Fibers and Textiles Technical Reference — 3M (2018)
- OXIPOL oxide CMC components (Keramikblech) — Pritzkow Spezialkeramik (2020)
- Developments in Oxide Fiber Composites (J. Am. Ceram. Soc. 89) — American Ceramic Society / F.W. Zok (2006)
- WHIPOX all-oxide CMC — processing and properties reports — DLR Institute of Materials Research (2012)
- ASM Handbook Vol. 21: Composites — Ceramic Matrix Composites — ASM International (2001)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.