MgO-dense
MgO-dense is a fully sintered, low-porosity magnesia ceramic offered at 96 % and 99 % purity and as a 99.9 % hot-pressed grade, distinct from the porous IEC C-820 body.
Reference datasheet — MgO-dense 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 99 condition
MgO-dense tempers and conditions
MgO-dense is supplied in 3 conditions, soft to hard. 99 is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
99Default 99 % MgO, pressureless sintered, dense | Standard dense magnesia for crucibles, thermocouple sheaths and molten-metal contact parts. | 95 | 550 HV | 45 W/m·K | ||
High-purity hot-pressed / HIPed MgO, near theoretical density | Choose for IR windows, high-purity single-crystal growth crucibles and maximum strength/thermal conductivity. | 130 | 650 HV | 55 W/m·K | ||
96–98 % MgO technical dense grade | Lower-cost dense magnesia for furnace linings, casting nozzles and setter plates where a silicate grain-boundary phase is tolerable. | 480 HV | 32 W/m·K |
What is MgO-dense?
MgO-dense is a fully sintered, low-porosity magnesia ceramic offered at 96 % and 99 % purity and as a 99.9 % hot-pressed grade, distinct from the porous IEC C-820 body. It combines the highest thermal conductivity among oxide ceramics at 45 W/m·K with a 1900 °C maximum service temperature, 300 GPa elastic modulus, 95 MPa tensile strength and strong resistance to molten metals, and is supplied as tubes, crucibles and pressed shapes. The main limit is hydration: MgO reacts with water and humid air, so coolant, storage and cleaning must be kept dry. Where moisture exposure cannot be avoided, alumina is the usual substitute. MgO-dense has a density of 3.55 g/cm³ (0.128 lb/in³), lighter than 66% of ceramic grades. It melts at 2,800°C (5,072 °F). MgO-dense has a tensile strength of 95 MPa (13.8 ksi), weaker than 52% of ceramic grades. The elastic modulus is 300 GPa (43.5 Msi).
What is MgO-dense used for?
- thermocouple sheaths
- molten metal crucibles
- refractory setters
- high-temperature electrical insulators
Advantages
- High service temperature — 1,900°C (3,452 °F), better than 94% of ceramic grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 84% of ceramic grades
- Easy to machine — 20/100, better than 82% of ceramic grades
Limitations
- Needs corrosion protection — 45/100, worse than 90% of ceramic grades
MgO-dense properties
Typical room-temperature values for MgO-dense-99; bars are the position among ceramic grades.
Physical4
MgO-dense has a density of 3.55 g/cm³ (0.128 lb/in³), lighter than 66% of ceramic grades. It melts at 2,800°C (5,072 °F).
Mechanical11
MgO-dense has a tensile strength of 95 MPa (13.8 ksi), weaker than 52% of ceramic grades. The elastic modulus is 300 GPa (43.5 Msi).
Thermal5
MgO-dense is rated for continuous service to 1,900°C (3,452 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 69% of ceramic grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical5
MgO-dense is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is fair (45/100), worse than 90% of ceramic grades.
Sustainability4
Producing a kilogram of MgO-dense takes about 40 MJ of energy and emits 3.2 kg of CO₂ — less than 88% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
MgO-dense's machinability is poor (20/100, better than 82% of ceramic 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 ceramic family
Yield strength against density for every ceramic grade FabDigit runs. MgO-dense is highlighted; hover a dot for its name, or open the interactive family chart.
Working with MgO-dense
Is MgO-dense easy to machine?
Green or bisque machining is preferred; fired parts require diamond grinding with dry or oil-based coolant — never water, which hydrates the surface.
Can MgO-dense be welded?
Not weldable; join by active-metal brazing (Ti/Zr-containing filler), glass sealing or mechanical clamping with compliant gaskets.
Can MgO-dense be formed, bent or molded?
Uniaxial/isostatic pressing or slip casting of magnesia powder, sintered 1600–1800 °C; hot pressing or HIP with LiF aid for transparent, near-theoretical-density bodies.
MgO-dense 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 |
|---|---|---|
| CaOgrain-boundary silicate former | 0.05 – 1 | 0.4 |
| SiO2 | 0.02 – 0.8 | 0.3 |
| Al2O3 | 0 – 0.3 | 0.1 |
| Fe2O3colours body brown at high levels | 0 – 0.3 | 0.1 |
| LiF or other sintering aidonly in hot-pressed/transparent grades | 0 – 0.5 | 0.1 |
| MgOpericlase, main phase | ≥ 98 (balance) |
What surface finishes work on MgO-dense?
Diamond lapping and polishing give optical-quality faces; store and ship in sealed dry packaging (desiccant) and pre-fire before use to remove adsorbed moisture.
Equivalent designations
Standards and trade names that resolve to MgO-dense in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- MgO
How much does MgO-dense cost?
MgO-dense is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
MgO-dense — frequently asked
What is MgO-dense used for?
MgO-dense is typically used for thermocouple sheaths, molten metal crucibles, refractory setters and high-temperature electrical insulators. In short: highest-conductivity oxide ceramic; 1900 °C service capability; moisture-sensitive, keep dry.
What is the tensile strength of MgO-dense?
MgO-dense has a typical tensile strength of 95 MPa (13.8 ksi) — weaker than 52% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is MgO-dense easy to machine?
Not especially — machinability is rated poor (20/100, better than 82% of ceramic grades). Green or bisque machining is preferred; fired parts require diamond grinding with dry or oil-based coolant — never water, which hydrates the surface.
Can MgO-dense be welded?
Not weldable; join by active-metal brazing (Ti/Zr-containing filler), glass sealing or mechanical clamping with compliant gaskets.
What surface finishes work on MgO-dense?
Diamond lapping and polishing give optical-quality faces; store and ship in sealed dry packaging (desiccant) and pre-fire before use to remove adsorbed moisture.
Can MgO-dense be formed, bent or molded?
Uniaxial/isostatic pressing or slip casting of magnesia powder, sintered 1600–1800 °C; hot pressing or HIP with LiF aid for transparent, near-theoretical-density bodies.
What is the maximum service temperature of MgO-dense?
MgO-dense is rated for continuous use to about 1,900°C (3,452 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does MgO-dense cost?
MgO-dense is a high-cost ceramic ($$$$), 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
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- Introduction to Ceramics (Kingery, Bowen, Uhlmann) — oxide property tables — Wiley (1976)
- Magnesia (MgO) crucible and tube technical data — Ortech Advanced Ceramics (2023)
- NIST-JANAF Thermochemical Tables (MgO) — NIST (1998)
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.