Green Silicon Carbide for Optical‑Glass Processing
Green Silicon Carbide (GC, SiC ≥ 98.5‑99%) has a Mohs hardness of 9.3. It features sharp grains, excellent self‑sharpening performance, low impurity content and superior thermal conductivity. As the mainstream abrasive for cold processing of optical glass, it is widely used for multi‑wire sawing, rough grinding, fine grinding, lapping and edge chamfering. Typical work‑pieces include camera lenses, automotive optical lenses, prisms, telescope lenses, medical endoscope lenses, quartz optical glass and other hard‑brittle optical components.
Compared with black silicon carbide, green silicon carbide delivers higher purity and lower iron impurities. It hardly causes surface contamination and scratches during processing, making it the preferred abrasive for optical‑glass manufacturing.
1. Common Green Silicon Carbide Grits for Optical‑Glass Processing (JIS / FEPA Standard)
| Processing Procedure | Function | Typical Grit |
|---|---|---|
| Multi‑wire Sawing (Slurry Sawing) | Slice optical‑glass blanks for high‑efficiency stock removal | F220‑F400 |
| Rough Grinding | Blank Forming Remove machining allowance and reshape blanks | F400‑F600 |
| Medium‑fine Grinding | Eliminate deep scratches from rough grinding and control subsurface damage | F800‑F1200 |
| Fine Lapping | Further reduce surface roughness to prepare base surface for final cerium‑oxide polishing | F1500‑F4000 |
| Edge Chamfering | Remove edge chipping and trim lens edges | F600‑F1000 |
2. Advantages of Green Silicon Carbide for Optical Glass
Sharp cutting & self‑sharpening property: Grain micro‑fracture occurs during grinding and continuously generates new cutting edges. It maintains stable processing efficiency and resists passivation and clogging.
High purity and low impurities: Acid‑washed material with low magnetic substance content reduces pitting and black‑spot contamination on glass surfaces.
Good thermal conductivity: Fast heat dissipation during grinding lowers thermal stress and reduces risks of glass chipping and cracking.
Narrow particle‑size distribution: Strict control over over‑size grains minimizes deep scratches and shortens subsequent polishing time.
3. Physical & Chemical Specifications
SiC ≥ 98.5‑99%
Fe₂O₃ ≤ 0.35%
Magnetic substance ≤ 0.02%
Rigorous D3 control to eliminate over‑size coarse particles
Acid‑washed and water‑treated powder for high cleanliness
