Ceramics balls
Product Features
Balls are made of ceramics (fine ceramics), are made from two types: non-oxide ceramics (such as silicon nitride) and oxide ceramics (such as alumina and zirconia). Among them, a silicon nitride ball weighs less than half the weight of a general steel ball but has hardness much higher than that of a general steel ball. Since they are strong and wear resistant under high temperatures, they are physically stable as well. Additionally, they also have excellent chemical properties of corrosion resistance, chemical resistance, and insulation performance.
Mechanical Property of Silicon Nitride Ball
| Density（kg/m3） | Hardness(HV) | Young's modulus(GPa） | Coefficient of thermal expansion(×10-6/℃） |
|---|---|---|---|
| 3.2～3.3×103 | 1400～1800 | 298～325 | 2.6～3.3 |
Usage Examples
- ・Bearings (Ceramic bearings, bearings for machine tools, etc.)
- ・Automotive parts (Hydraulic lash adjusters, common rail injectors, etc.)
- ・Wind power generation (Generators) and more
Hydraulic lash adjusters
(courtesy of OTICS Corporation)
Product Specification
1.Type and Feature of Material
| Material | Feature | |
|---|---|---|
| Non-oxide ceramics | Silicon nitride（Si3N4） | Low thermal expansion coefficient, high thermal shock resistance, and excellent thermal and creep resistance |
| Silicon carbide（SiC） | Excellent corrosion and wear resistance, as well as high thermal resistance (almost no strength degradation up to 1,600°C) | |
| Oxide ceramics | Alumina（Al2O3） | Excellent ambient temperature strength, corrosion resistance, and insulation performance |
| Zirconia（ZrO2） | High melting point with good chemical stability and low thermal conductivity High impact strength |
2.Dimensions and dimensional accuracy
Dimensions 0.8mm～1-7/8（47.6mm）
| Ball grades | Ball diameter variation（Max） （μm） | Deviation from spherical form（Max） （μm） | Surface roughness（Max） （μmRa） | Variation of ball lot diameter（Max） （μm） |
|---|---|---|---|---|
| G3 | 0.08 | 0.08 | 0.010 | 0.13 |
| G5 | 0.13 | 0.13 | 0.014 | 0.25 |
| G10 | 0.25 | 0.25 | 0.020 | 0.5 |
| G16 | 0.4 | 0.4 | 0.025 | 0.8 |
| G20 | 0.5 | 0.5 | 0.032 | 1 |
| G24 | 0.6 | 0.6 | 0.040 | 1.2 |
| G28 | 0.7 | 0.7 | 0.050 | 1.4 |
| G40 | 1 | 1 | 0.060 | 2 |
| G60 | 1.5 | 1.5 | 0.080 | 3 |
※According to JIS B1563（Rolling bearing-Silicon nitride balls) and ISO 3290-2（Rolling bearing-Ceramic balls）