Silicon Nitride Ceramic Bearing and balls
Silicon nitride (Si3N4) high thermal conductivity substrate
High thermal conductivity silicon nitride ceramic substrate
Features
►High strength: Bending strength is about twice that of AL2O3 and ALN substrates.
►High thermal conductivity: It is more than 3 times higher than AL2O3 substrate.
►Light and thin: its thickness can reach 1/2 of AlN substrate
►Excellent thermal shock resistance: its thermal expansion coefficient is close to that of silicon.
|
Item |
Unit |
Al2O3 |
AIN |
Si3N4 |
|
|
Density |
g/cm2 |
3.75 |
3.3 |
3.22 |
|
|
Thickness |
mm |
0.3175~1.0 |
0.4~2.5 |
0.238~0.635 |
|
|
Surface roughness level (Ra) |
μm |
0.4 |
0.2 |
0.4 |
|
|
Mechanical properties |
bending strength |
Mpa |
310~400 |
300~450 |
650 |
|
Young's modulus |
Gpa |
330 |
320 |
310 |
|
|
Vickers hardness |
Gpa |
14 |
11 |
15 |
|
|
fracture toughness |
Mpa.ml/2 |
3~4 |
2~4 |
5~7 |
|
|
Thermal expansion coefficient |
10 -6/K |
7.1~8.1 |
4.5~4.6 |
2.6 |
|
|
Thermal conductivity |
W/(m.K) |
20~30 |
160~255 |
60~120 |
|
|
Specific heat |
J/(kg/K) |
750 |
720 |
680 |
|
|
Electrical characteristics |
Dielectric constant |
/ |
9~10 |
8~9 |
7~9 |
|
Dielectric loss tangent |
...10-3 |
0.2 |
0.3 |
0.4 |
|
|
Volume resistivity |
Ω.m |
＞1012 |
＞1012 |
＞1012 |
|
|
Breakdown voltage |
kv/mm |
＞12 |
＞14 |
＞14 |
|
Silicon nitride ceramic balls
Silicon nitride ceramic balls have a series of excellent properties such as high strength, high rigidity, high abrasion resistance and so on. Ceramic cylindrical rollers have the advantage of electrical insulation, which is effective to avoid current damage to bearing rings and rolling elements caused by the electric current generated by the bearing during operation.
After a long time of work, the traditional bearing roller body will be insufficient in lubricant, which will lead to fatigue damage and life reduction of the bearing. However, the self-lubricating function of silicon nitride ceramic cylindrical roller bearing solves this problem.
Even if the bearing seal is very tight, there is still a risk of contaminants entering the bearing operating space. However, the silicon nitride ceramic cylindrical roller is non-magnetic, which makes it difficult for pollutants to be adsorbed on the rolling body. By using such kind of roller, it effectively prevents the entire bearing operating space from being polluted.
Advantages and applications of ceramic cylindrical roller bearing
It has the characteristics of impact resistance, wear resistance, high temperature resistance, high contact fatigue life and so on.
It is widely used in rolling mill bearings.
Levels of roller （Unit:μm）
|
Tolerance level |
Ra |
||
|
Rolling surface（max） |
End surface（max） |
Angle of chamfer（max） |
|
|
0 |
0.1 |
0.125 |
1.25 |
|
Ⅰ |
0.125 |
1.16 |
1.25 |
|
Ⅱ |
0.16 |
0.25 |
2.5 |
|
Ⅲ |
0.25 |
0.32 |
2.5 |
Silicon nitride ceramic balls for wind power generation
Silicon nitride ceramic balls have the advantage of electrical insulation, which is effective to avoid current damage to bearing rings and rolling elements caused by the electric current generated by the bearing during operation.
After a long time of work, the traditional bearing roller body will be insufficient in lubricant, which will lead to fatigue damage and life reduction of the bearing. However, the self-lubricating function of silicon nitride ceramic cylindrical roller bearing solves this problem.
Even if the bearing seal is very tight, there is still a risk of contaminants entering the bearing operating space. However, the silicon nitride ceramic cylindrical roller is non-magnetic, which makes it difficult for pollutants to be adsorbed on the rolling body. By using such kind of roller, it effectively prevents the entire bearing operating space from being polluted.
KSINO bearing balls for wind power generation have a series of advantages such as high hardness, low friction coefficient, light weight, corrosion resistance, non-magnetic, electrical insulation, high temperature resistance and so on. Such kind of balls effectively avoid the electric corrosion and lubrication wear of the bearings caused by the current generated during the operation of the wind power generation bearings. This product is an indispensable material in the field of wind power bearing, and its accuracy grade can reach G10.
The major product sizes include 47.625mm, 50.8mm and 53.975mm.
Silicon nitride guide roller
Silicon nitride guide rollers are used in casting industry.
Compared with metal guide roller and alloy guide roller, silicon nitride guide roller has superior advantages, including high temperature resistance, high hardness, high toughness, impact resistance and oxidation resistance. At the same time, the silicon nitride guide roller is oil-free, self-lubricating, low density, light weight. Especially, the service life of silicon nitride guide roller is more than ten times that of the alloy guide roller.
Silicon nitride cover layer for air
Silicon nitride protective cover layer is widely applied to corrosive gas channels to slow down the gas flow.
Silicon nitride protective cover layer has very good corrosion resistance. Meantime, it has high hardness, high and low temperature resistance. Thus, it can be stably used in high temperature and corrosive impurity gas.
Depending on the good corrosion performance, Silicon nitride protective cover layer will be different from metal protective cover player which will bring its own impurities into the product. Thus, it can ensure the product purity.
Silicon nitride protective cover layer has gradually placed the metal ones in corrosive environment.
