ZrB2
ZrB₂ is an ultra-high-temperature ceramic (UHTC) zirconium diboride with an extreme melting point, a 489 GPa elastic modulus and metal-like thermal conductivity of 75 W/m·K at a density of 6.09 g/cm³.
Reference datasheet — ZrB2 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 HP condition
ZrB2 tempers and conditions
ZrB2 is supplied in 4 conditions, soft to hard. HP 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 |
|---|---|---|---|---|---|---|
Carbon-fibre / chopped-fibre toughened UHTC | Pick when damage tolerance and thermal-shock survival matter more than absolute hardness — fibres raise toughness at the cost of oxidation life and strength scatter. | 1,200 HV | 45 W/m·K | |||
Pressureless sintered ZrB2 | Choose when complex near-net shapes or larger parts are needed and 5–10 % lower strength / slight residual porosity is acceptable. | 1,700 HV | 60 W/m·K | |||
HPDefault Hot-pressed monolithic ZrB2 | Baseline dense monolithic UHTC: pick for electrodes, molten-metal hardware and short-duration high-heat-flux parts where SiC contamination is unwanted. | 2,200 HV | 75 W/m·K | |||
ZrB2–20 vol % SiC | The workhorse UHTC: SiC particles double the flexural strength and form a protective silica scale, so pick it for oxidizing service to ~1600–1800 °C (leading edges, nozzle throats). | 2,300 HV | 78 W/m·K |
Supply forms, finishes and certifications
Ways ZrB2 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
PWD | ZrB2 sintering powder, 99 %, 1–5 µm | Supply form |
What is ZrB2?
ZrB₂ is an ultra-high-temperature ceramic (UHTC) zirconium diboride with an extreme melting point, a 489 GPa elastic modulus and metal-like thermal conductivity of 75 W/m·K at a density of 6.09 g/cm³. It is specified for hypersonic leading edges and rocket nozzle inserts, and is supplied hot-pressed (HP), pressureless-sintered (PS), as ZrB₂–20% SiC and SiC/carbon-fibre composite variants, and as powder. Oxidation resistance is good, but continuous service is held near 1200 °C unless a SiC- or HfO₂-based coating is added, it cannot be fusion welded, and fired parts require diamond grinding or EDM. SiC or Si₃N₄ are lower-cost choices where the boride's temperature capability and electrical conductivity are not needed. ZrB2 has a density of 6.09 g/cm³ (0.22 lb/in³), heavier than 68% of ceramic grades. It melts at 3,245°C (5,873 °F). ZrB2 has a tensile strength of 280 MPa (40.6 ksi), stronger than 67% of ceramic grades. The elastic modulus is 489 GPa (70.9 Msi).
What is ZrB2 used for?
- hypersonic leading edges
- rocket nozzle inserts
- molten metal crucibles
- cutting tool additives
Advantages
- Stiff — 489 GPa (70.9 Msi), better than 77% of ceramic grades
Limitations
- High embodied carbon — 28 kg CO₂/kg, worse than 84% of ceramic grades
ZrB2 properties
Typical room-temperature values for ZrB2-HP; bars are the position among ceramic grades.
Physical3
ZrB2 has a density of 6.09 g/cm³ (0.22 lb/in³), heavier than 68% of ceramic grades. It melts at 3,245°C (5,873 °F).
Mechanical11
ZrB2 has a tensile strength of 280 MPa (40.6 ksi), stronger than 67% of ceramic grades. The elastic modulus is 489 GPa (70.9 Msi).
Thermal5
ZrB2 is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 75 W/m·K (43.3 BTU/hr·ft·°F), better than 73% of ceramic grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical2
ZrB2 has an electrical resistivity of 9.2×10⁻⁸ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (70/100), worse than 59% of ceramic grades.
Sustainability4
Producing a kilogram of ZrB2 takes about 320 MJ of energy and emits 28 kg of CO₂ — more than 78% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
ZrB2's machinability is not recommended (8/100, better than 69% 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. ZrB2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZrB2
Is ZrB2 easy to machine?
Green machining before sintering is preferred; fired parts need diamond grinding, and because ZrB2 is metallically conductive it can be wire/sinker EDM'd — a major advantage over SiC and Si3N4.
Can ZrB2 be welded?
Not weldable; join by active brazing (Ti/Zr-bearing AgCu or Ni-based fillers), diffusion bonding to Nb/Mo, or co-sintering.
Can ZrB2 be formed, bent or molded?
Densified by hot pressing (1850–2050 °C, 20–30 MPa) or SPS; pressureless sintering above 2000 °C needs B4C/C/MoSi2 aids, so near-net shapes are made by cold isostatic pressing plus green machining.
ZrB2 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 |
|---|---|---|
| B | 18.5 – 19.6 | 19.2 |
| Hfnatural companion of zirconium, not removed | 0.5 – 2.5 | 1.5 |
| Osurface B2O3/ZrO2 on powder; must be reduced for densification | ≤ 1 | 0.5 |
| Cfrom carbothermal route / carbon sintering aid | ≤ 0.5 | 0.2 |
| Femilling pickup | ≤ 0.2 | 0.05 |
| SiC0 in monolithic grade; 15–30 vol % in ZrB2–SiC composite variants | ≈ 0 | 0 |
| Zrstoichiometric ZrB2; commercial Zr carries 1–2.5 % Hf | ≥ 78.5 (balance) |
What surface finishes work on ZrB2?
Diamond lapping/polishing to sub-µm Ra; for long oxidizing exposure apply or co-sinter SiC/HfO2-based coatings, and avoid abrasive blasting which leaves strength-limiting flaws.
How much does ZrB2 cost?
ZrB2 is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ZrB2 — frequently asked
What is ZrB2 used for?
ZrB2 is typically used for hypersonic leading edges, rocket nozzle inserts, molten metal crucibles and cutting tool additives. In short: EDM-machinable UHTC; metal-like thermal conductivity; highest-temperature boride family.
What is the tensile strength of ZrB2?
ZrB2 has a typical tensile strength of 280 MPa (40.6 ksi) — stronger than 67% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is ZrB2 easy to machine?
Not especially — machinability is rated not recommended (8/100, better than 69% of ceramic grades). Green machining before sintering is preferred; fired parts need diamond grinding, and because ZrB2 is metallically conductive it can be wire/sinker EDM'd — a major advantage over SiC and Si3N4.
Can ZrB2 be welded?
Not weldable; join by active brazing (Ti/Zr-bearing AgCu or Ni-based fillers), diffusion bonding to Nb/Mo, or co-sintering.
What surface finishes work on ZrB2?
Diamond lapping/polishing to sub-µm Ra; for long oxidizing exposure apply or co-sinter SiC/HfO2-based coatings, and avoid abrasive blasting which leaves strength-limiting flaws.
Can ZrB2 be formed, bent or molded?
Densified by hot pressing (1850–2050 °C, 20–30 MPa) or SPS; pressureless sintering above 2000 °C needs B4C/C/MoSi2 aids, so near-net shapes are made by cold isostatic pressing plus green machining.
What is the maximum service temperature of ZrB2?
ZrB2 is rated for continuous use to about 1,200°C (2,192 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does ZrB2 cost?
ZrB2 is a high-cost ceramic ($$$$), 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
- Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications — Wiley/The American Ceramic Society (2014)
- Refractory Diborides of Zirconium and Hafnium (J. Am. Ceram. Soc. review) — American Ceramic Society (2007)
- ASM Engineered Materials Handbook Vol. 4 — Ceramics and Glasses — ASM International (1991)
- ISO 26845 — Fine ceramics, vocabulary and test-condition reporting — ISO (2008)
- Boride / UHTC component datasheets (CoorsTek, Kyocera, / ZrB2 powder) — various producers (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.