Advantages:
- Excellent chemical stability,reduces impurity'bring in,improved the
quality of aluminum casting products.
- High temperature resistance,which remain the same strength and
hardness when the temperature of aluminum liquid comes to
800℃-900℃.
- High density with low porosity,it can be long-term using in
aluminum liquid,which decrease the residue,in order to improve the
service life and reduce the maintenance cost.
- It is non-wetting to aluminum liquid,which can highly reduce the
aluminum attachment on the surface of the tube.
- Excellent resistance to thermal shock,which can improve the working
life
Due to the high density with low porosity, high temperature
stability,excellent resistance to thermal shock and excellent
corrosion resistance,silicon nitride material has a very broad
application prospects in the cast aluminum industry on equipment
parts.Currently,Our company has developed andproduced series of
high performance silicon nitride ceramic products for cast aluminum
industry using,including silicon nitride riser tube,silicon nitride
heater protection tube,rotating shaft,rotor and silicon nitride
protection tube for thermocouple,etc..
Silicon Nitride Related Data
| Main component | 99%Al2O3 | S-SiC | ZrO2 | Si3N4 |
|
Physical
Property | Density | g/cm3 | 3.9 | 3.1 | 6 | 3.2 |
| Water Absorption | % | 0 | 0.1 | 0 | 0.1 |
| Sinter Temperature | °C | 1700 | 2200 | 1500 | 1800 |
Mechanical
Property | Rockwell Hardness | HV | 1700 | 2200 | 1300 | 1400 |
| Bend Strength | kgf/mm2 | 3500 | 4000 | 9000 | 7000 |
| Compression Intensity | Kgf/mm2 | 30000 | 20000 | 20000 | 23000 |
Thermal
Property | Maximum working
temperature | °C | 1500 | 1600 | 1300 | 1400 |
thermal expansion
coefficient
0-1000°C | /°C | 8.0*10-6 | 4.1*10-6(0-500°C) | 9.5*10-6 | 2.0*10-6(0-500°C) |
| 5.2*10-6(500-1000°C) | 4.0*10-6(500-1000°C) |
| Thermal Shock resistance | T(°C) | 200 | 250 | 300 | 400-500 |
| Thermal Conductivity | W/m.k(25°C | 31 | 100 | 3 | 25 |
| 300°C) | 16 | 100 | 3 | 25 |
Electrical
Property | Resisting rate of Volume | ◎.cm | | | | |
| 20°C | >1012 | 106-108 | >1010 | >1011 |
| 100°C | 1012-1013 | – | – | >1011 |
| 300°C | >1012 | – | – | >1011 |
Insulation Breakdown
Intensity | KV/mm | 18 | semiconductor | 9 | 17.7 |
| Dielectric Constant (1 MHz) | (E) | 10 | – | 29 | 7 |
| Dielectric Dissipation | (tg o) | 0.4*10-3 | – | – | – |
