Hexagonal Boron Nitride Powder
Pyroflux India supplies high-purity hexagonal boron nitride powder from stock in Noida, in particle-size grades from 3 µm to 50 µm and packs from 1 kg to bulk. h-BN is a white, lamellar, chemically inert solid often called white graphite: it lubricates like graphite but leaves no carbon behind, keeps working in vacuum and inert atmospheres, and resists oxidation to far higher temperatures. That combination makes it the default choice wherever a black carbon-based lubricant would contaminate the part, and its unusual pairing of high thermal conductivity with electrical insulation is the whole basis of the thermal-interface-material market. We stock it loose for direct use as a dry lubricant and mould dust, as a functional filler for compounders of greases, potting resins, engineering plastics and thermal pastes, and we supply h-BN / boron oxide blends to a customer’s specification with PPAP documentation where required.
Typical h-BN Powder Specification
| BN content | 99% minimum |
|---|---|
| Particle size (D50) | Grades from 3 µm to 50 µm; tell us the film thickness or bond line you work to |
| Appearance | White, free-flowing lamellar powder |
| Crystal form | Hexagonal (not cubic BN, which is the hard abrasive form) |
| Pack sizes | 1 kg, 5 kg, 10 kg, 25 kg and bulk |
| Typical uses | Thermal interface materials, thermally conductive plastics, high-temperature greases, mould dusting, dry lubrication, electrostatic dummy-block lubrication, cosmetics-grade enquiries on request |
Blends of hexagonal boron nitride with boron oxide, and other boron-based powder blends, are supplied to a customer’s specification with the documentation an OEM supply chain expects, including PPAP.
Which Particle Size Does Your Job Need?
| Use | Grade | Why |
|---|---|---|
| Thermal interface materials, gap fillers, pads | Coarser grades (20–50 µm) or a bimodal mix | Larger platelets pack into a more conductive network; a fine fraction fills the gaps |
| Thermally conductive engineering plastics | 10–30 µm | Balances conductivity against melt flow and mechanical properties |
| High-temperature greases and anti-seize | 3–10 µm | Fine platelets stay suspended and shear smoothly |
| Dry-film lubricant and release coatings | 3–10 µm | Smooth, thin, well-covering films |
| Mould dusting, dummy-block electrostatic coating | 10–30 µm | Free-flowing, easy to meter, good release |
| Compounding into your own BN coating | Match to your film thickness | Pyroflux can also supply the finished suspension |
Not sure? Send us the application and the bond line or film thickness and we will recommend a grade and send a 1 kg sample.
Why Engineers Specify Hexagonal Boron Nitride
| Property | Typical value | What it means in practice |
|---|---|---|
| Maximum service temperature | ≈850–900 °C in air; ≈1400 °C in vacuum; 1200–2000 °C in inert gas | Atmosphere matters more than temperature |
| Thermal conductivity | Strongly anisotropic; hot-pressed parts typically 11–130 W/m·K by grade and direction | Moves heat away from a working face or a chip |
| Electrical behaviour | Volume resistivity above 10¹³ Ω·cm | Thermally conductive and electrically insulating at the same time |
| Hardness | Mohs ≈2–2.5 | Will not abrade dies, moulds or screws; cubic BN is the hard form |
| Density | ≈2.1–2.3 g/cm³ | Roughly half that of alumina |
| Wetting by molten metal | Not wetted by most molten metals, slags or glass | The core reason it works as a release agent |
| Chemical stability | Inert to most acids at room temperature | Non-toxic, non-contaminating, suitable for clean processes |
Common Questions
What is the difference between hexagonal and cubic boron nitride?
The same compound in two crystal structures with almost opposite properties. Hexagonal BN is layered like graphite and soft (about 2 on the Mohs scale), which makes it a lubricant and release agent. Cubic BN is diamond-like and among the hardest materials known, used for cutting tools and abrasives. Everything on this page is hexagonal BN.
Which particle size should I choose?
As a rule the largest particle should not exceed the thickness of the finished coating or part. Coarser grades give better thermal performance in filled compounds; finer grades give smoother coatings and better coverage for lubricant and release duties. Tell us the film thickness or bond line and we will recommend one.
Can you supply blends to a specification?
Yes. Hexagonal boron nitride blended with boron oxide or other boron-based powders is supplied to the customer’s specification, with certificates of analysis per lot and PPAP documentation where the supply chain requires it.
What is the minimum order?
Powder is supplied from 1 kg. Larger packs are 5 kg, 10 kg, 25 kg and bulk; lead times are quoted with the price.
Do you also make the coatings?
Yes. If you are buying powder to compound your own boron nitride coating or release agent, ask about the Pyrolube suspensions first; the finished product is usually cheaper than the development time.
Tell Us The Process; We Will Recommend The Grade
Substrate, process temperature, atmosphere and how you prefer to apply it. That is everything we need to point you at the right product, send a sample, or quote.
- Phone
- +91 98181 87838
- sales@pyroflux.in
- Office
- G-5, Sector 63, Noida 201301, Uttar Pradesh, India
- Factory
- G-15, Sector 63, Noida 201301, Uttar Pradesh, India
- Hours
- Monday to Saturday, 9 am to 6 pm IST