六硼氮化硼(hBN)粉末
Hex-Boron Nitride (hBN) Powder六硼氮化硼(hBN)粉末六硼氮化硼(hBN)粉末crons to 30 micronsable idea. .Hexagonal Boron Nitride (hBN) is also known as ‘White Graphite’, has similar (hexagonal) crystal structure as of Graphite. This crystal structure provides excellent lubricating properties. hBN is much superior to Graphite and has following characteristics: Physical Properties of Hexagonal Boron Nitride CAS Number 10043-11-5 Chemical Formula BN Crystal Structure Hexagonal Color White Density (gm/cm3 ) 2.3 Melting Point 3000o C Dissociates Coefficient of Friction (COF) 0.15 to 0.70 Dielectric Constant (MHz) 4 Dielectric Breakdown strength 35 KV/mm Youngs Modulus (MPa) 20-102 Thermal Expansion Coefficient @ 25o C-1000o C 1 x 10-6/ o C (Parallel to press dir.) 4 x 10-6/ o C (Perpendicular to press dir.) Thermal Conductivity (at 293 K, directional average) 0.08 cal/ cm.sec.K Temperature Stability 1000o C in Air 1400o C in Vacuum 1800o C in Inert atmosphere • Excellent Lubricating Properties due to low Coefficient of Friction at 0.15 to 0.70 • Good Chemical Inertness • Electrical Insulator • Thermal Conductor (result: better heat dissipation) • High Temperature Stability, 1000o C in Air, 1400o C in Vacuum and 1800o C in Inert gas • Low Thermal Expansion • Low Dielectric Constant • High Load bearing properties • Non-Wetting: hBN is not wetted by Glasses, Salts and (most) metals, therefore it provides strong resistance to chemical attack • Easy Machineability (in hot pressed state). Complex shapes can be machined from hot pressed structure.