High-performance silicon nitride ceramic materials developed for the aluminum industry has significantly improved
thermal and mechanical properties than similar products. On this
basis, the "L-shaped high thermal conductivity submerged heating
"Appliance" will bring revolutionary progress to aluminum
industrial equipment.
Silicon nitride ceramic has become the material of choice for the
outer protection tube of electric heaters and gas heaters due to
its excellent high temperature performance.
Due to its good high-temperature strength and high thermal shock
resistance, the product can withstand the thermal load of the
high-temperature heating element or burner for a long time, and the
service life is more than one year;
Advantage:
Compared with the traditional upper radiant heating method, the
energy saving efficiency reaches 20%-30%, and the overheating and
oxidation of the upper aluminum liquid is effectively avoided.
Silicon nitride ceramics hardly react with the molten aluminum, so
it will not pollute the molten aluminum, which is beneficial to
maintain the purity of the heated molten aluminum;
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 | – | – | – |
