China 4-Hole Insulated Alumina Ceramic Tube/Pipe, Find details about China Alumina Ceramic Tube, Alumina Ceramic from 4-Hole Insulated Alumina Ceramic Tube/Pipe
With good thermostability,insulation,temperature stability etc properties, 2 bores ceramic insulators tube are mainl used in B-type,S-type and new type tungsten-rhenium thermocouple sleeves.
With all the properties of 2 bores insulators tube,one-point two-temperature is also realizable in 4 bores ceramic insulatores tube.
All products through the German DIN standards: DIN43724 / DIN43725 /DIN40680
We only make high purity alumina ceramics
1. High-purity alumina content 99.3% -99.5%, other alumina ceramics 92% -99%.
2. The color of high purity alumina product is milky white, and other products are pink or white. The higher the purity, the more transparent the color.
3. Alumina is a refractory material, the higher the purity, the better the refractory effect
4. After high-purity alumina ceramics are fired and cooled in a 1800-degree high-temperature kiln, the products are not easy to break when they encounter high temperatures. Other ceramics are fired at 1500 ºC ~ 1800 ºC.
5. The volume density of high-purity alumina> 3.92 g / cm3 has a smooth surface and is not easily corroded by chemicals. The bulk density of other ceramics is> 3.70 g / cm3 ~> 3.85 g / cm3.
6. High purity alumina has good hardness and good wear resistance.
7. High purity alumina products have a longer service life.
NAME | CONTENT(%) |
Al2O3 | 99.3-99.5(99.7) |
SiO2 | 0.3-0.5 |
CaO+MgO | 0.2-0.3 |
K2O+Na2O | 0.2-0.35 |
Fe2O3 | <0.1 |
OTHER | <0.05 |
NO. | Property | Unit | Alumina |
1 | Al2O3 | % | >99.3 |
2 | SiO2 | % | - |
3 | Density | g/cm3 | 3.88 |
4 | Water absorption | % | 0.01 |
5 | Cold compressive strength | MPa | 350 |
6 | 20ºC leakage rates | Torr/L.sec | <10-11 |
7 | Twisting in high temperature | mm | 0.2 allowed in 1600ºC |
8 | Bonding in high temperature |
| not bonded in 1600ºC |
9 | 20-1000ºC coefficient ofthermalexpansion | mm.10-6/ºC.m | 8.2 |
10 | Thermal conductivity | W/m.k | 25 |
11 | Electric insulation strength | KV/mm | 20 |
12 | 20ºCdirect current insulation resistance | Ohm/cm | 1014 |
13 | High-temperature insulation resistance | 1000ºC MΩ | ≥0.08 |
1300ºC MΩ | ≥0.02 | ||
14 | Thermal shock resistance |
| 4 times not cracked in 1550ºC |
15 | Maximum working temperature | ºC | 1800 |