BeO 998-HP
Grade
998-HP = beO 99.8 % hot-pressed / near-theoretical-density grade
Choose the hot-pressed, near-theoretical-density 99.8 % quality for extreme power-density heat sinks, nuclear moderator parts and high-frequency windows; near-zero porosity yields 310 W/m·K.
Values for the 998-HP condition
Other BeO tempers and conditions
BeO is listed in 3 conditions; see the grade overview at BeO.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
995Default BeO 99.5 % | Industry workhorse at 99.5 % purity: choose when thermal conductivity, strength and metallizability must be balanced for microwave tubes, laser heat sinks and thick-film power substrates. | — | 130 | — | 1,200 HV | 275 W/m·K |
BeO 99.0 % | Pick the lower-cost pressureless-sintered 99.0 % purity quality for power-resistor substrates and insulating parts that need less than 250 W/m·K thermal conductivity. | — | — | — | 1,100 HV | 240 W/m·K |
998-HPThis page BeO 99.8 % hot-pressed / near-theoretical-density grade | Choose the hot-pressed, near-theoretical-density 99.8 % quality for extreme power-density heat sinks, nuclear moderator parts and high-frequency windows; near-zero porosity yields 310 W/m·K. | — | — | — | 1,280 HV | 310 W/m·K |
What is BeO 998-HP?
BeO 998-HP is BeO in the 998-HP grade — choose the hot-pressed, near-theoretical-density 99.8 % quality for extreme power-density heat sinks, nuclear moderator parts and high-frequency windows; near-zero porosity yields 310 W/m·K. BeO 998-HP has a tensile strength of 130 MPa (18.9 ksi), stronger than 53% of ceramic grades. The elastic modulus is 390 GPa (56.6 Msi). BeO 998-HP has a density of 2.99 g/cm³ (0.108 lb/in³), lighter than 75% of ceramic grades. It melts at 2,530°C (4,586 °F). 995 is the default condition FabDigit quotes; 998-HP is available on request or by drawing note.
Advantages
- Conducts heat well — 310 W/m·K (179.1 BTU/hr·ft·°F), better than 99% of ceramic grades
- High service temperature — 1,900°C (3,452 °F), better than 94% of ceramic grades
- Lightweight — 2.99 g/cm³ (0.108 lb/in³), better than 75% of ceramic grades
- Good corrosion resistance — 86/100, better than 75% of ceramic grades
Limitations
- High embodied carbon — 30 kg CO₂/kg, worse than 91% of ceramic grades
BeO 998-HP properties
Typical room-temperature values for BeO 998-HP; 12 are specific to this condition. Other listed values are BeO reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical4
BeO 998-HP has a density of 2.99 g/cm³ (0.108 lb/in³), lighter than 75% of ceramic grades. It melts at 2,530°C (4,586 °F).
Mechanical11
BeO 998-HP has a tensile strength of 130 MPa (18.9 ksi), stronger than 53% of ceramic grades. The elastic modulus is 390 GPa (56.6 Msi).
Thermal5
BeO 998-HP is rated for continuous service to 1,900°C (3,452 °F). It conducts heat at 310 W/m·K (179.1 BTU/hr·ft·°F), better than 99% of ceramic grades. Thermal expansion is 7 µm/m·K (3.89 µin/in·°F).
Electrical5
BeO 998-HP is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (86/100), better than 75% of ceramic grades.
Sustainability4
Producing a kilogram of BeO 998-HP takes about 450 MJ of energy and emits 30 kg of CO₂ — more than 94% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
BeO 998-HP's machinability is not recommended (4/100, worse than 85% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BeO 998-HP
Is BeO easy to machine?
After sintering, only diamond grinding or laser machining is practical, and all work must be run wet with HEPA extraction; dry dust generation is prohibited. Turn or mill complex geometry in the green state and sinter afterwards.
Can BeO be welded?
Not weldable; hermetic joints are made by Mo-Mn metallising plus nickel plating, then brazing to Kovar or copper with Ag-Cu filler.
Can BeO be formed, bent or molded?
Formed by dry pressing, isostatic pressing or tape casting for thin substrates, then sintered at 1500–1800 °C. Linear shrinkage is about 15–20 %, so tooling must be oversized accordingly.
What surface finishes work on BeO?
Diamond lapping and polishing reach Ra below 0.1 µm. Surfaces accept thick-film or thin-film metallisation (Ti-Pt-Au, Mo-Mn, DBC copper) for soldering and circuit routing.
BeO 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 |
|---|---|---|
| BeOmain crystalline phase, hexagonal wurtzite structure | 99.5 – 99.9 | 99.5 |
| MgOcommon sintering aid, inhibits grain growth | 0 – 0.3 | 0.15 |
| SiO2impurity/sintering aid | 0 – 0.2 | 0.08 |
| Al2O3impurity | 0 – 0.15 | 0.05 |
| Fe2O3 + CaO + otherbalance of trace impurities, total <0.1 % | balance | — |
BeO 998-HP — frequently asked
What is BeO 998-HP used for?
BeO 998-HP is typically used for RF/microwave substrates, laser diode heat sinks, high-power electronic packages and nuclear moderator components. In short: highest-conductivity oxide insulator; toxic dust, contained processing; alternative to aluminium nitride.
What is the tensile strength of BeO 998-HP?
BeO 998-HP has a typical tensile strength of 130 MPa (18.9 ksi) — stronger than 53% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is BeO 998-HP easy to machine?
Not especially — machinability is rated not recommended (4/100, worse than 85% of ceramic grades). After sintering, only diamond grinding or laser machining is practical, and all work must be run wet with HEPA extraction; dry dust generation is prohibited. Turn or mill complex geometry in the green state and sinter afterwards.
Can BeO 998-HP be welded?
Not weldable; hermetic joints are made by Mo-Mn metallising plus nickel plating, then brazing to Kovar or copper with Ag-Cu filler.
What surface finishes work on BeO 998-HP?
Diamond lapping and polishing reach Ra below 0.1 µm. Surfaces accept thick-film or thin-film metallisation (Ti-Pt-Au, Mo-Mn, DBC copper) for soldering and circuit routing.
Can BeO 998-HP be formed, bent or molded?
Formed by dry pressing, isostatic pressing or tape casting for thin substrates, then sintered at 1500–1800 °C. Linear shrinkage is about 15–20 %, so tooling must be oversized accordingly.
What is the maximum service temperature of BeO 998-HP?
BeO 998-HP 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.
Sources
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- Beryllium Oxide (BeO) Ceramic Property Data — American Beryllia / Materion Ceramics (2022)
- Engineering ceramics thermophysical property compilation — NIST / Ceramic Industry data tables (2020)
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.