PBN (Pyrolytic Boron Nitride) is an anisotropic, high temperature ceramic, which exhibits a unique combination of high electrical resistance and good thermal conductivity.
This inert, non-porous compound is exceptionally pure by virtue of its synthesis process (high temperature/low pressure chemical vapour deposition).
We can supply at very competitive prices. PBN crucibles are not stocked items, delivery is usually 14 to 30 days. We have a minimum order number of 4 items of any single size.
For crystal growth applications, PBN crucibles and boats are used to contain the melt as it is transformed from a polycrystalline state to a single crystal. Its ultra-high purity and unique thermal properties make PBN the ideal crystal growth vessel.
|Apparent Density, gm/cc:||1.95 - 2.22|
|Tensile Strength, MPa (psi)||40 (6000)|
|Flexural Strength, MPa (psi)||80 (12,000)|
|Thermal Conductivity, W/moC 'ab' 60, 'c' 2
CTE, mm/mm/oC (1000oC) 'ab'
|2 x 10-6|
|Dielectric Strength, D.C. volts/mm||2 x 105|
|Dielectric Constant 'ab' 5.2, 'c'||3.4|
|Total Metallic Impurities, ppm||< 100|
|Max. Suggested use (oC)||2500|
The Pyrolytic process is that of a vapor deposition. It can be considered to be a crystalline form of Boron Nitride, whereas most BN crucibles are pressed from powder and then machined, these are created from the BN vapor and deposited onto a mandrel. (a pyrolytic graphite mandrel for easy removal.) The benefits are that the PBN crucibles are not porous, most materials will not stick to the sides because there are no pores for the materials to reside in. They are more pure than standard BN, and they can resist any chemical attack better than standard BN, again because of its density. PBN is the only material that is resistive to anhydrous HF attack at temps above 1600 C.