MgO Ceramic
MgO Ceramic is a high-purity magnesia body offered in 96 %, 99.5 % and hot-pressed 99.9 % purities plus a fused-magnesia (FM) grade, combining a very high melting point with thermal conductivity unusually high for an oxide insulator.
Reference datasheet — MgO Ceramic 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 99.5 condition
MgO Ceramic tempers and conditions
MgO Ceramic is supplied in 4 conditions, soft to hard. 99.5 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
96 % MgO | Lowest-cost sintered magnesia with CaO/SiO₂ silicate bond — refractory shapes, crucibles and furnace linings where purity is not critical. | 70 | 520 HV | 25 W/m·K | ||
99.5Default 99.5 % MgO | Standard high-purity technical magnesia — crucibles for reactive metal melting, thermocouple protection tubes and high-temperature insulators. | 100 | 620 HV | 40 W/m·K | ||
99.9 % MgO | Fully dense hot-pressed magnesia for IR windows, optical and ultra-high-temperature insulator applications where translucency and maximum thermal conductivity are needed. | 130 | 720 HV | 52 W/m·K | ||
Fused (electro-fused) magnesia grain / bonded shapes | Electric-arc fused periclase with large crystals — best slag corrosion resistance and highest thermal conductivity, used as grain for refractory bricks and as MI heating-element filler. | 600 HV | 45 W/m·K |
What is MgO Ceramic?
MgO Ceramic is a high-purity magnesia body offered in 96 %, 99.5 % and hot-pressed 99.9 % purities plus a fused-magnesia (FM) grade, combining a very high melting point with thermal conductivity unusually high for an oxide insulator. It is used for refractory and high-temperature electrical insulation parts made by pressing, slip casting in non-aqueous media, tube extrusion or hot pressing. Typical values are density 3.55 g/cm³, tensile strength 100 MPa, elastic modulus 300 GPa, thermal conductivity 40 W/m·K and service to 1700 °C. Thermal shock resistance is poor and the corrosion resistance score of 35 reflects its tendency to hydrate in moist air, so parts must be kept dry; alumina is the alternative where water exposure or thermal cycling is expected. MgO Ceramic 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 Ceramic has a tensile strength of 100 MPa (14.5 ksi), stronger than 50% of ceramic grades. The elastic modulus is 300 GPa (43.5 Msi).
What is MgO Ceramic used for?
- refractory crucibles
- thermocouple sheath insulation
- heating element cores
- high-temperature furnace linings
Advantages
- High service temperature — 1,700°C (3,092 °F), better than 90% of ceramic grades
- Low embodied carbon — 3 kg CO₂/kg, better than 88% of ceramic grades
- Easy to machine — 22/100, better than 83% of ceramic grades
Limitations
- Needs corrosion protection — 35/100, worse than 100% of ceramic grades
MgO Ceramic properties
Typical room-temperature values for MgO Ceramic-99.5; bars are the position among ceramic grades.
Physical4
MgO Ceramic 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 Ceramic has a tensile strength of 100 MPa (14.5 ksi), stronger than 50% of ceramic grades. The elastic modulus is 300 GPa (43.5 Msi).
Thermal5
MgO Ceramic is rated for continuous service to 1,700°C (3,092 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), better than 67% of ceramic grades. Thermal expansion is 13.5 µm/m·K (7.5 µin/in·°F).
Electrical5
MgO Ceramic 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 (35/100), worse than 100% of ceramic grades.
Sustainability4
Producing a kilogram of MgO Ceramic takes about 40 MJ of energy and emits 3 kg of CO₂ — less than 88% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
MgO Ceramic's machinability is poor (22/100, better than 83% 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 Ceramic is highlighted; hover a dot for its name, or open the interactive family chart.
Working with MgO Ceramic
Is MgO Ceramic easy to machine?
Machine green or bisque-fired bodies with carbide tooling; fired parts require diamond grinding with dry or oil coolant — never water, which hydrates the surface.
Can MgO Ceramic be welded?
Not weldable; join by ceramic cement, glass frit or active-metal brazing (Ti/Zr-containing filler) in vacuum, allowing for the large CTE mismatch with metals.
Can MgO Ceramic be formed, bent or molded?
Uniaxial or isostatic dry pressing, slip casting in non-aqueous media, extrusion of tubes, or hot pressing; sintering at 1600–1800 °C, often with CaO/B₂O₃ or LiF aids to reach full density.
MgO Ceramic 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 |
|---|---|---|
| CaOmain sintering-aid / impurity | 0.02 – 0.3 | 0.1 |
| SiO2forms silicate bond phase | 0.01 – 0.25 | 0.08 |
| Fe2O3 | 0.01 – 0.15 | 0.03 |
| Al2O3 | 0.01 – 0.15 | 0.03 |
| B2O3sometimes added as densification aid | 0 – 0.05 | 0.01 |
| MgOpericlase; balance of high-purity technical grade | ≥ 99.5 (balance) |
What surface finishes work on MgO Ceramic?
Diamond lap/polish for optical or seal faces; parts must be dried, vacuum-baked and stored in a desiccator or hermetically sealed to prevent hydration and spalling.
Equivalent designations
Standards and trade names that resolve to MgO Ceramic in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- MgO
How much does MgO Ceramic cost?
MgO Ceramic is a standard-cost ceramic ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
MgO Ceramic — frequently asked
What is MgO Ceramic used for?
MgO Ceramic is typically used for refractory crucibles, thermocouple sheath insulation, heating element cores and high-temperature furnace linings. In short: highest service temperature oxide; thermally conductive electrical insulator; moisture-sensitive; requires sealed storage.
What is the tensile strength of MgO Ceramic?
MgO Ceramic has a typical tensile strength of 100 MPa (14.5 ksi) — stronger than 50% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is MgO Ceramic easy to machine?
Not especially — machinability is rated poor (22/100, better than 83% of ceramic grades). Machine green or bisque-fired bodies with carbide tooling; fired parts require diamond grinding with dry or oil coolant — never water, which hydrates the surface.
Can MgO Ceramic be welded?
Not weldable; join by ceramic cement, glass frit or active-metal brazing (Ti/Zr-containing filler) in vacuum, allowing for the large CTE mismatch with metals.
What surface finishes work on MgO Ceramic?
Diamond lap/polish for optical or seal faces; parts must be dried, vacuum-baked and stored in a desiccator or hermetically sealed to prevent hydration and spalling.
Can MgO Ceramic be formed, bent or molded?
Uniaxial or isostatic dry pressing, slip casting in non-aqueous media, extrusion of tubes, or hot pressing; sintering at 1600–1800 °C, often with CaO/B₂O₃ or LiF aids to reach full density.
What is the maximum service temperature of MgO Ceramic?
MgO Ceramic is rated for continuous use to about 1,700°C (3,092 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does MgO Ceramic cost?
MgO Ceramic is a standard-cost ceramic ($$), cheaper than about 71% 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)
- Refractories Handbook (Schacht, ed.) — CRC Press (2004)
- Technical magnesia (MgO) ceramic property sheets — CoorsTek / Ortech / Kyocera (2023)
- GB/T 2273 / GB/T 24411 — SAC (2019)
- MatWeb / NIST ceramics property records for magnesium oxide — MatWeb, NIST (2024)
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.