Si3N4 Silicon Nitride Bearing Rollers
The description of Si3N4 ceramic parts
Silicon nitride is a man-made compound synthesized through several different chemical reaction methods. Parts are pressed and sintered by well-developed methods to produce a ceramic with a unique set of outstanding properties. The material is dark gray to black in color and can be polished to a very smooth reflective surface, giving parts a striking appearance. High-performance silicon nitride materials were developed for automotive engine wear parts, such as valves and cam followers, and have proven effective. The cost of the ceramic parts never dropped enough to make the ceramics feasible in engines and turbochargers. The very high-quality bodies developed for these demanding high-reliability applications are available today and can be used in many severe mechanical, thermal, and wear applications.
The prime features of Silicon nitride ceramic part1. Low density: 3.2 g/cm
3 with lightweight than most other technical ceramics
2. Superior hardness, it’s one of most hardest technical ceramics among others
3. Great wear resistance due to its exceptional hardness and self-lubricity
4. Low coefficient of thermal expansion and high thermal conductivity (20 W/m.k)
5. Great thermal shock resistance, it’s up to 1000ºC under the special atmosphere
6. High mechanical strength and well resistance to impact than other advanced ceramics
7. Heat & high-temperature resistance, The max. service temperature can be up to 1300ºC
8. Chemical and corrosion resistance, resistant to almost all inorganic acids and many organic acids
9. At the same time, Silicon nitride is a high-performance electrical insulation material
The specification of ceramic parts
Material option |
Silicon nitride(Si3N4), Zirconia (ZrO2), Alumina(Al2O3), Silicon carbide(SiC) |
Forming methods |
Dry pressed, Ceramic injection molding, Hot pressed, ISO pressed |
Specification |
OD can be from 1 to 50mm, length can be from 10mm to 800mm |
Precision processing |
CNC machining, Precision grinding, Polishing, Lapping, |
Tolerance |
The tolerance of OD and ID can be 0.001mm, and the tolerance of length can be 0.001mm |
Key parameters |
Roughness to be 0.02mm, Parallelism to be 0.001mm |
Surface quality |
Free of cracks, foreign contamination, mirror surface better than Ra0.02 |
The typical application of Si3N4 ceramics
It’s widely used for producing bearings, shafts, gas turbine blades, mechanical seal rings, permanent molds, steam nozzle, the heated surfaces of engine components
The gallery of other technical ceramic parts
Product Parameters
Datasheet of Technical ceramics
Property |
Unit |
Material |
Si3N4 |
99.5% Al2O3 |
99% Al2O3 |
96%
Al2O3 |
ZrO2 |
Density |
g/cm3 |
≥3.20 |
≥3.90 |
≥3.85 |
≥3.65 |
≥6.0 |
Water absorption |
% |
– |
0 |
0 |
0 |
0 |
Hardness |
HV |
– |
1700 |
1700 |
1500 |
1300 |
Flexural strength |
Mpa |
≥600 |
≥379 |
≥338 |
≥320 |
≥1200 |
Compressive strength |
Mpa |
≥2500 |
≥2240 |
≥2240 |
≥2000 |
≥1990 |
Fracture toughness |
Mpa m1/2 |
6 |
4-5 |
4-5 |
3-4 |
6.5-8 |
Max. service temperature |
ºC |
1200 |
1675 |
1600 |
1450 |
1000 |
Coefficient of thermal expansion (CTE) |
1×10 -6 /ºC |
3.2 |
6.5~8.0 |
6.2~8.0 |
5.0~8.0 |
8.0~9.5 |
Thermal shock |
T(ºC) |
≥600 |
≥250 |
≥200 |
≥220 |
≥300 |
Thermal conductivity(25ºC) |
W/m.k |
20 |
30 |
29 |
24 |
3 |
Volume resistivity |
ohm.cm |
|
|
|
|
|
25ºC |
– |
>1 x 10 14 |
>1 x 10 14 |
>1 x 10 14 |
>1 x 10 11 |
300ºC |
– |
1 x 10 12 |
8 x 10 11 |
10 12 -10 13 |
1 x 10 10 |
500ºC |
– |
5 x 10 10 |
2 x 10 9 |
1 x 10 9 |
1 x 10 6 |
Insulation strength |
KV/mm |
|
19 |
18 |
18 |
17 |
Dielectric constant(1Mhz) |
(E) |
6 |
9.7 |
9.5 |
9.5 |
29 |
Why choose us?
We have in-housing comprehensive manufacturing types of equipment, including forming, sintering, CNC machining, precision grinding, laser cutting, and so on, which helps us to control the quality very well. Also, it greatly benefits cost control.
Remark:
We have the complete quality-control system per ISO9001, including IQC, IPQC, QA, and OQC processes.
Certifications