7-8mm Pressureless Sintered Silicon Carbide Grinding Balls
Product Overview
7–8 mm pressureless sintered silicon carbide (SiC) grinding balls are ceramic grinding media manufactured from nano-scale SiC powder via high-temperature sintering at atmospheric pressure. With their relatively low density and extremely high hardness, they are ideal grinding media for stirred mills.
Manufacturing Process
| Process Step |
Key Points |
Description |
| Raw material preparation |
Ultra-fine high-purity SiC powder |
Synthetic SiC is ground into an ultra-fine, high-purity powder |
| Mixing and batching |
Addition of sintering aids |
Sintering aids reduce the temperature required for densification, enabling pressureless sintering |
| Ball blank forming |
Rolling forming |
Rough ball blanks of the required dimensions are produced |
| Sintering |
High-temperature pressureless sintering |
Sintering is carried out at 1950–2150 °C in a non‑oxidizing atmosphere under normal pressure |
| Cooling and finishing |
Natural cooling |
After natural cooling, finishing is performed if necessary to obtain the finished grinding balls |
Core Properties
| Property |
Value |
Remarks |
| Density |
>3.15 g/cm³ |
Lower than that of alumina and zirconia, beneficial for low energy consumption |
| Vickers hardness |
2000–2500 HV |
Mohs hardness 9.5, extremely low wear rate |
| Fracture toughness |
3.0–4.0 MPa·m¹/² |
Very high hardness but limited toughness; avoid severe impact |
| Maximum service temperature |
1600 °C |
Excellent high‑temperature stability |
| Wear resistance |
Wear rate 0.05–0.10‰/5 h |
Suitable for long‑duration continuous grinding |
| Color |
Black |
Easy to identify |
Main Application Scenarios
- Stirred mill / vertical sand mill grinding: Low density and high hardness enable efficient wet ultra‑fine grinding.
- Grinding of ultra‑hard materials: When grinding quartz sand, silicon carbide, and similar materials, efficiency is more than 40% higher than that of alumina balls.
- High‑purity grinding: Grinding the same material (e.g., SiC powder) introduces no foreign impurities, eliminating the need for iron removal.
- Corrosion‑resistant / high‑temperature environments: Suitable for coatings, textiles, pigments, printing, dyeing, and other industries.
Advantages & Characteristics
- High strength and wear resistance: Wear rate is only 1/50 that of ordinary steel balls.
- Corrosion resistance: Resists acids and alkalis, making it suitable for harsh chemical environments.
- High‑temperature resistance: Maintains high strength up to 1000 °C and has a low coefficient of thermal expansion.
- Non‑magnetic, non‑conductive, and insulating: Can be used in magnetic fields and allows oil‑free lubrication.
Comparison with Other Grinding Media
| Parameter |
Pressureless Sintered SiC Ball |
Alumina Ball (99%) |
Zirconia Ball |
| Density (g/cm³) |
3.15–3.2 |
3.95 |
6.0 |
| Mohs hardness |
9.5 |
9 |
8.5–9 |
| Vickers hardness (HV) |
2000–2500 |
1800 |
1200–1600 |
| Max. service temperature (°C) |
1600 |
1000 |
400 |
| Wear resistance |
Excellent |
Good |
Excellent |
| Impact toughness |
Low |
Medium |
Relatively high |
| Cost |
High |
Low |
Medium to high |
| Typical application |
Ultra‑hard material grinding |
Fine grinding, general use |
Balancing hardness and toughness |
Usage Precautions
- Avoid severe impact to prevent brittle fracture.
- Recommended for stirred mills; not suitable for coarse grinding applications that involve heavy impact.
- The relatively high cost means these balls are intended for demanding applications.
For further information or to discuss your specific requirements, please contact us directly.