ZRB2-20SIC
Reinforced grade
ZRB2-20SIC = 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).
Values for the ZRB2-20SIC condition
Other ZrB2 tempers and conditions
ZrB2 is listed in 4 conditions; see the grade overview at ZrB2.
- ZRB2-SIC-CF
- PS
- HP
- ZRB2-20SIC
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 |
ZRB2-20SICThis page 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 |
What is ZRB2-20SIC?
ZRB2-20SIC is ZrB2 in the ZRB2-20SIC grade — 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). ZRB2-20SIC has a tensile strength of 280 MPa (40.6 ksi), stronger than 67% of ceramic grades. The elastic modulus is 500 GPa (72.5 Msi). ZRB2-20SIC has a density of 5.5 g/cm³ (0.199 lb/in³), heavier than 54% of ceramic grades. It melts at 3,245°C (5,873 °F). HP is the default condition FabDigit quotes; ZRB2-20SIC is available on request or by drawing note.
Advantages
- High service temperature — 1,700°C (3,092 °F), better than 90% of ceramic grades
- Stiff — 500 GPa (72.5 Msi), better than 77% of ceramic grades
- Conducts heat well — 78 W/m·K (45.1 BTU/hr·ft·°F), better than 75% of ceramic grades
Limitations
- High embodied carbon — 28 kg CO₂/kg, worse than 84% of ceramic grades
ZRB2-20SIC properties
Typical room-temperature values for ZRB2-20SIC; 14 are specific to this condition. Other listed values are ZrB2 reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
ZRB2-20SIC has a density of 5.5 g/cm³ (0.199 lb/in³), heavier than 54% of ceramic grades. It melts at 3,245°C (5,873 °F).
Mechanical11
ZRB2-20SIC has a tensile strength of 280 MPa (40.6 ksi), stronger than 67% of ceramic grades. The elastic modulus is 500 GPa (72.5 Msi).
Thermal5
ZRB2-20SIC is rated for continuous service to 1,700°C (3,092 °F). It conducts heat at 78 W/m·K (45.1 BTU/hr·ft·°F), better than 75% of ceramic grades. Thermal expansion is 5.9 µm/m·K (3.28 µin/in·°F).
Electrical2
ZRB2-20SIC has an electrical resistivity of 2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (80/100), better than 56% of ceramic grades.
Sustainability4
Producing a kilogram of ZRB2-20SIC takes about 320 MJ of energy and emits 28 kg of CO₂ — more than 78% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
ZRB2-20SIC's machinability is not recommended (6/100, better than 61% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZRB2-20SIC
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.
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.
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) | — |
ZRB2-20SIC — frequently asked
What is ZRB2-20SIC used for?
ZRB2-20SIC 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 ZRB2-20SIC?
ZRB2-20SIC 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 ZRB2-20SIC easy to machine?
Not especially — machinability is rated not recommended (6/100, better than 61% 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 ZRB2-20SIC 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 ZRB2-20SIC?
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 ZRB2-20SIC 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 ZRB2-20SIC?
ZRB2-20SIC 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
- 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.