High Precision Fine Silicon Nitride Ceramic Bearing Ball
Description:
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 with a striking appearance. High-performance silicon nitride
materials were developed for automotive engine wear parts, such as
valves and cam followers, and proven effective.
Technical Parameters:
| Mechanical behavior | Unit | Al2O3 | SiC | Si3N4 | ZrO2 |
| Colour | ------- | Light yellow | black | black | white,black |
| Density | g/cm3 | 3.95 | 3.15 | 3.2 | 6 |
| Bending strength | MPa | 300～400 | 400～500 | 800～1200 | 950～1200 |
| Elastic modulus E | GPa | 380 | 350 | 300-320 | 210 |
| Poisson's ratio | | 0.22 | 0.14 | 0.26 | -------- |
| Hardness | Hv | 1800 | 2000～2500 | 1400～1700 |
1100～1300 |
| HRC | 80 | 85～90 | 75～80 | 70～75 |
| Fracture toughness | MPa·m1/2 | 3.0～4.0 | 3.0～4.0 | 5.0～7.0 | 8.0～10.0 |
| Maximum use temperature | ℃ | 1000 | 1300 | 400 | 400 |
| Thermal expansion coefficient | 10-6/℃ | 8.4 | 4 | 3.3 | 10.3 |
Advantages:
1. Low density: 3.2 g/cm3 with lightweight than most of other
technical ceramics
2. Superior hardness, it's one of most hardest technical ceramic
than 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 advance 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 materia.
Application:
Most ceramic balls are mounted in the bearing (high-speed bearing,
high precision bearing, vacuum bearing, high/low-temperature
bearing, nonmagnetic bearing, high precision ball screws) for the
high technology industry, such as aerospace and national defense
and etc. The ceramic balls can also be used for chemistry,
metallurgy, medical treatment, food industry, oilfield, electronic
engineering and etc.
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