Boron Nitride Ceramic characteristic
Boron Nitride Solids are made by hof pressing hexagonal Boron Nitride powders.The color of BN products is milky true density is 2.27g/cm3．Mohs value is 2．they have a high melting point(sublimale point is 3000℃) When in a condition of inert atmosphere, their maximum service temperatu re can reach to 2800℃ Their thermal conductivity Is 25W/(m·K),similar to stainless steel.And coefficient of liner expansion is between 2.0 x 10/℃ to 6.5 x 10℃
They have a high quality of heat-resistance and shock-resistance and they can work effieienlly after severaI hundred of 1000℃←→20℃ cycles. Their oxidalIon resIstance is poor,and their chemicai properties are stable，they have a high corrosion-resistance of acid．alk molten metal and glass.BN products cannol have chemical reaction with most molten metais．such as Cu．staieless steeI．Fe．Sn Zn and Sb Mechanical strength is low just a ltitle more than that of graphite，volume resistance Is between 25~1050℃．10″~10 n·cm they are good insulators Electric breakdown strength is between 30 kV/Cm to 40 kV/cm,which Is three times than than of aluminum oxide Thermocompression products are distinctly anisotropic,they can be used to finish cut,and the precision of lathe can reach to 0.01mm
| General Properties | Unit | |||||
| BN content | 95-98% | 98-99% | >99.5% | 60% | 45% | |
| Color | white | white | white | white | Grey | |
| Typical Applications | General purpose | Outstanding Moisture Resistance,Refractory,Dislectric Strength | Resistance,Refractory,Dielectnic Strength Extreme Corrosion Resistance,Thermal Conductivity,Purity | Extreme Thermal Conductivity,Moisture,Resistance,Dielectric Strength | Extreme Wear Resistance & Comasion Resistance in moiten metais applicattions | |
| Directionality | ||||||
| Mechalical Properties | ||||||
| Flexural Strength | MPa | 94 65 | 59 45 | 22 21 | 62 34 | 144 107 |
| Youngs Modulus | GPa | 47 74 | 40 60 | 17 17 | 71 71 | |
| RT Compression | MPa | 143 186 | 96 | 25 | 218.69 253.83 | |
| Open Properties | % | 2.84 | 19.3 | 6.724 | 1.066 | |
| Density | g/cc min | 2 | 2 | 1.9 | 2.1 | 2.9 |
| Hardness-Knoop | kg/mm2 | 20 | 16 | 4 | 100 | |
| Thermal Properties | ||||||
| Thermal Conductivity at 25℃ | W/mK | 30 34 | 27 29 | 78 130 | 11 29 | 24 34 |
| Coeff. of Thermal Expansion(10-6) | ||||||
| 25-400℃ | 3.0 3.0 | 0.6 0.4 | -2.3 -0.7 | 3.0 0.4 | 4.1 3.4 | |
| 400-800℃ | 2.0 1.4 | 1.1 0.8 | -2.5 1.1 | 2.5 0.1 | 5.6 4.3 | |
| 800-1200℃ | 1.9 1.8 | 1.5 0.9 | 1.6 0.4 | 3.0 0.1 | 7.2 5.2 | |
| 1200-1600℃ | 5.0 4.8 | 2.8 2.7 | 0.9 0.3 | 4.6 3.4 | ||
| 1600-1900℃ | 7.2 6.1 | 0.5 0.9 | ||||
| Specific Heat at 25 ℃ | J/gk | 0.86 | 0.81 | 0.81 | 0.77 | 0.64 |
| Max.Temp-Oxidizing/Inert | 850/1200℃ | 850/1150℃ | 850/2000℃ | 1000℃+ | 850/1600℃ | |
| Electrical Properties | ||||||
| Dielectric constant at 1MHZ | 4.6 4.2 | 4.3 4.0 | 4.0 4.0 | 4.5 3.8 | ||
| Dissipation factor at 1MHZ | 1.2E-03 3.4E-03 |
1.5E-03 2.1E-03 |
1.2E-0.3 3.0E-04 |
3.0E-03 6.7E-03 |
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| Dielectric Strength | KV/mm | 88 | >10 | 79 | 66 | >9 |
| RT Resistivity | Ω cm | >1013 >1014 | >1013 >1013 | >1013 >1014 | >1013 >1014 | >1014 >1015 |