CBN MICRO
Grade
also Borazon
MICRO = microcrystalline / polycrystalline CBN micron powder
Choose for fine lapping/polishing slurries and high-toughness resin-bond superfinishing where self-sharpening blocky micro-grain is wanted.
Values for the MICRO condition
Other CBN tempers and conditions
CBN is listed in 3 conditions; see the grade overview at CBN.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
MICROThis page Microcrystalline / polycrystalline CBN micron powder | Choose for fine lapping/polishing slurries and high-toughness resin-bond superfinishing where self-sharpening blocky micro-grain is wanted. | — | 350 | 0 | 4,000 HV | 300 W/m·K |
Low-CBN-content sintered blank | Choose for continuous finish hard turning of 55–65 HRC bearing/gear steels where wear resistance and edge integrity beat impact toughness. | — | — | — | 2,800 HV | 44 W/m·K |
High-CBN-content sintered blank | Choose for interrupted/heavy hard turning, milling of grey and chilled cast iron, hardfacing and sintered iron where impact toughness and heat conduction dominate. | — | — | — | 3,200 HV | 120 W/m·K |
What is CBN MICRO?
CBN MICRO is CBN in the MICRO grade — choose for fine lapping/polishing slurries and high-toughness resin-bond superfinishing where self-sharpening blocky micro-grain is wanted. The elastic modulus is 700 GPa (101.5 Msi). CBN MICRO has a density of 3.46 g/cm³ (0.125 lb/in³), lighter than 68% of ceramic grades. It melts at 2,973°C (5,383 °F).
Advantages
- Stiff — 700 GPa (101.5 Msi), better than 99% of ceramic grades
- Conducts heat well — 300 W/m·K (173.3 BTU/hr·ft·°F), better than 99% of ceramic grades
- Polishes to a fine finish — 92/100, better than 89% of ceramic grades
- Good corrosion resistance — 91/100, better than 84% of ceramic grades
Limitations
- High embodied carbon — 55 kg CO₂/kg, worse than 97% of ceramic grades
CBN MICRO properties
Typical room-temperature values for CBN MICRO; 14 are specific to this condition. Other listed values are CBN reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical4
CBN MICRO has a density of 3.46 g/cm³ (0.125 lb/in³), lighter than 68% of ceramic grades. It melts at 2,973°C (5,383 °F).
Mechanical8
The elastic modulus is 700 GPa (101.5 Msi).
Thermal5
CBN MICRO is rated for continuous service to 1,100°C (2,012 °F). It conducts heat at 300 W/m·K (173.3 BTU/hr·ft·°F), better than 99% of ceramic grades. Thermal expansion is 4.8 µm/m·K (2.67 µin/in·°F).
Electrical3
CBN MICRO has an electrical resistivity of 1×10⁹ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (91/100), better than 84% of ceramic grades.
Sustainability3
Producing a kilogram of CBN MICRO takes about 900 MJ of energy and emits 55 kg of CO₂ — more than 96% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
CBN MICRO's machinability is not recommended (2/100, worse than 100% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CBN MICRO
Is CBN easy to machine?
Not machinable by conventional means — shaped by diamond grinding/lapping, laser or wire-EDM (only conductive TiC/TiN- or metal-bonded PCBN is EDM-capable).
Can CBN be welded?
Not weldable; PCBN wafers are vacuum-brazed to WC-Co carbide substrates with Ag-Cu-Ti active filler below ~900 °C to avoid back-conversion to hBN.
Can CBN be formed, bent or molded?
Formed only by HPHT synthesis/sintering at 5–8 GPa and 1350–1800 °C; grit is then shape-graded, coated (Ni/Ti) and bonded into resin, vitrified or electroplated wheels.
What surface finishes work on CBN?
Cutting edges are diamond-lapped or honed to a T-land/chamfer; abrasive grit is nickel- or titanium-clad to improve bond retention and heat transfer.
CBN 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 |
|---|---|---|
| Bstoichiometric BN, zincblende structure | 43 – 44 | 43.6 |
| Li/Mg/Ca (catalyst residue)nitride catalyst residues in HPHT grit; imparts amber/black colour | 0 – 1 | 0.3 |
| AlN/AlB2 binder (PCBN-H only)sintering aid in high-content polycrystalline blanks | 5 – 15 | 10 |
| TiC/TiN binder (PCBN-L only)ceramic binder phase in low-content polycrystalline blanks | 35 – 55 | 45 |
| N | ≥ 56 (balance) | — |
CBN MICRO — frequently asked
What is CBN MICRO used for?
CBN MICRO is typically used for cutting tool inserts (PCBN), grinding wheel abrasive, honing hardened steel and high-speed machining of superalloys. In short: second-hardest known material; ferrous-safe superabrasive; hard-turning tool phase.
Is CBN MICRO easy to machine?
Not especially — machinability is rated not recommended (2/100, worse than 100% of ceramic grades). Not machinable by conventional means — shaped by diamond grinding/lapping, laser or wire-EDM (only conductive TiC/TiN- or metal-bonded PCBN is EDM-capable).
Can CBN MICRO be welded?
Not weldable; PCBN wafers are vacuum-brazed to WC-Co carbide substrates with Ag-Cu-Ti active filler below ~900 °C to avoid back-conversion to hBN.
What surface finishes work on CBN MICRO?
Cutting edges are diamond-lapped or honed to a T-land/chamfer; abrasive grit is nickel- or titanium-clad to improve bond retention and heat transfer.
Can CBN MICRO be formed, bent or molded?
Formed only by HPHT synthesis/sintering at 5–8 GPa and 1350–1800 °C; grit is then shape-graded, coated (Ni/Ti) and bonded into resin, vitrified or electroplated wheels.
What is the maximum service temperature of CBN MICRO?
CBN MICRO is rated for continuous use to about 1,100°C (2,012 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- ASM Handbook Vol. 16: Machining — Superabrasives and PCBN tooling — ASM International (1989)
- PCBN grade and CBN abrasive technical data — Element Six (2023)
- CBN turning grade selection data (CB7015/CB7025 class) — Sandvik Coromant (2023)
- GB/T 23536 (Cubic boron nitride) — SAC/ (2009)
- Semiconductor and elastic properties of cubic boron nitride — Landolt-Börnstein / Ioffe compilations (2001)
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.