MgO SINT-99
Grade
SINT-99 = sintered 99 %
Use the pressed and sintered opaque 99 % ceramic for non-optical high-temperature duty to 1700 °C — crucibles, thermocouple insulating tubes and furnace parts — as the economical option.
Values for the SINT-99 condition
Other MgO tempers and conditions
MgO is listed in 4 conditions; see the grade overview at MgO.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
alternate-orientation single crystal | Choose this non-(100) oriented wafer when the film demands a specific lattice symmetry, for example hexagonal-phase layers or magnetic tunnel junctions. | — | 110 | 0 | 650 HV | 50 W/m·K |
SINT-99This page Sintered 99 % | Use the pressed and sintered opaque 99 % ceramic for non-optical high-temperature duty to 1700 °C — crucibles, thermocouple insulating tubes and furnace parts — as the economical option. | — | — | — | 550 HV | 30 W/m·K |
SC-100Default SC | Use as the default: the (100) orientation is the most common substrate for epitaxy of perovskite oxide films and also serves as a polished infrared window. | — | — | — | 600 HV | 50 W/m·K |
hot-pressed transparent polycrystalline MgO (IR window) | Pick the hot-pressed transparent polycrystalline form for large-aperture infrared windows and domes when higher strength and freedom from cleavage planes outweigh slightly lower transmission. | — | — | — | 640 HV | 40 W/m·K |
What is MgO SINT-99?
MgO SINT-99 is MgO in the SINT-99 grade — use the pressed and sintered opaque 99 % ceramic for non-optical high-temperature duty to 1700 °C — crucibles, thermocouple insulating tubes and furnace parts — as the economical option. MgO SINT-99 has a tensile strength of 100 MPa (14.5 ksi), stronger than 80% of glass grades. The elastic modulus is 260 GPa (37.7 Msi). MgO SINT-99 has a density of 3.45 g/cm³ (0.125 lb/in³), heavier than 66% of glass grades. It melts at 2,825°C (5,117 °F). SC-100 is the default condition FabDigit quotes; SINT-99 is available on request or by drawing note.
Advantages
- High service temperature — 1,700°C (3,092 °F), better than 100% of glass grades
- Stiff — 260 GPa (37.7 Msi), better than 95% of glass grades
- Conducts heat well — 30 W/m·K (17.3 BTU/hr·ft·°F), better than 92% of glass grades
- Tough — resists crack growth — 1.2 MPa·√m (1.09 ksi·√in), better than 91% of glass grades
Limitations
- Needs corrosion protection — 35/100, worse than 88% of glass grades
- Hard to polish — 50/100, worse than 88% of glass grades
- Difficult to machine — 8/100, worse than 84% of glass grades
MgO SINT-99 properties
Typical room-temperature values for MgO SINT-99; 14 are specific to this condition. Other listed values are MgO reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
MgO SINT-99 has a density of 3.45 g/cm³ (0.125 lb/in³), heavier than 66% of glass grades. It melts at 2,825°C (5,117 °F).
Mechanical11
MgO SINT-99 has a tensile strength of 100 MPa (14.5 ksi), stronger than 80% of glass grades. The elastic modulus is 260 GPa (37.7 Msi).
Thermal5
MgO SINT-99 is rated for continuous service to 1,700°C (3,092 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), better than 92% of glass grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical5
MgO SINT-99 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental2
Corrosion resistance is fair (35/100), worse than 88% of glass grades.
Sustainability4
Producing a kilogram of MgO SINT-99 takes about 45 MJ of energy and emits 3 kg of CO₂ — less than 58% of glass grades. Typical recycled content is 0%.
Manufacturability2
MgO SINT-99's machinability is not recommended (8/100, worse than 84% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MgO SINT-99
Is MgO easy to machine?
Diamond sawing, grinding and lapping only. The {100} cleavage planes chip readily, so orient cuts away from cleavage directions and use low feeds with ample water-free coolant.
Can MgO be welded?
Not weldable as a ceramic. Join to metals by active-metal brazing (Ti/Ag-Cu) or by Mo-Mn metallization followed by nickel plating and brazing, matching CTE to avoid thermal-stress cracking.
Can MgO be formed, bent or molded?
Single crystals are grown by arc fusion or directional solidification and then sliced. Polycrystalline parts are dry- or isostatically pressed from high-purity magnesia and sintered at 1600-1750 °C; transparent grades require hot pressing or HIP.
What surface finishes work on MgO?
CMP gives epi-ready surfaces below 0.5 nm Ra. Store polished parts in dry nitrogen or vacuum bags; IR windows are normally AR-coated, which also serves as a moisture barrier, and a 400-600 °C vacuum anneal before use removes surface hydroxide.
MgO 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 |
|---|---|---|
| CaOtypical trace impurity | ≤ 0.03 | 0.01 |
| SiO2typical trace impurity | ≤ 0.02 | 0.01 |
| Al2O3typical trace impurity | ≤ 0.02 | 0.01 |
| Fe2O3colouring impurity, degrades IR transmission | ≤ 0.01 | 0 |
| MgOoptical/substrate grade purity; Mg 60.3 wt %, O 39.7 wt % | ≥ 99.9 (balance) | — |
MgO SINT-99 — frequently asked
What is MgO SINT-99 used for?
MgO SINT-99 is typically used for IR windows, thin-film epitaxial substrates and high-temperature optics. In short: lattice-matched oxide substrate; hygroscopic, dry storage required; 1200 °C service limit.
What is the tensile strength of MgO SINT-99?
MgO SINT-99 has a typical tensile strength of 100 MPa (14.5 ksi) — stronger than 80% of glass grades. Strength varies by condition: see the 4 listed tempers.
Is MgO SINT-99 easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 84% of glass grades). Diamond sawing, grinding and lapping only. The {100} cleavage planes chip readily, so orient cuts away from cleavage directions and use low feeds with ample water-free coolant.
Can MgO SINT-99 be welded?
Not weldable as a ceramic. Join to metals by active-metal brazing (Ti/Ag-Cu) or by Mo-Mn metallization followed by nickel plating and brazing, matching CTE to avoid thermal-stress cracking.
What surface finishes work on MgO SINT-99?
CMP gives epi-ready surfaces below 0.5 nm Ra. Store polished parts in dry nitrogen or vacuum bags; IR windows are normally AR-coated, which also serves as a moisture barrier, and a 400-600 °C vacuum anneal before use removes surface hydroxide.
Can MgO SINT-99 be formed, bent or molded?
Single crystals are grown by arc fusion or directional solidification and then sliced. Polycrystalline parts are dry- or isostatically pressed from high-purity magnesia and sintered at 1600-1750 °C; transparent grades require hot pressing or HIP.
What is the maximum service temperature of MgO SINT-99?
MgO SINT-99 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.
Sources
- The Crystran Handbook of Infra-Red and Ultra-Violet Optical Materials — Magnesium Oxide — Crystran Ltd (2023)
- ASM Engineered Materials Handbook Vol.4: Ceramics and Glasses — ASM International (1991)
- CRC Materials Science and Engineering Handbook (4th ed.) — CRC Press (2015)
- MgO single crystal substrate specifications — MTI Corporation / SurfaceNet GmbH (2024)
- Handbook of Optical Constants of Solids — MgO dispersion data — Academic Press (1998)
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.