Le carbure de silicium vert (SiC vert), souvent abrégé en silicium vert ou carbone vert dans l’industrie, est l’abrasif de base pour le rodage et le polissage de précision des faces d’extrémité des fibres. Les grains 4000, 6000 et 8000 sont les plus couramment utilisés dans les huiles de rodage (également appelées liquide ou pâte de rodage).
1. Aperçu général
Carbure de silicium vert (GC / SiC vert) : Ce matériau se caractérise par une pureté élevée (SiC ≥ 98,5 % à 99 %), une dureté élevée (dureté Mohs : 9,4), un tranchant exceptionnel et d’excellentes propriétés d’auto-affûtage. Il est particulièrement adapté à l’usinage ultra-précis de matériaux fragiles et durs tels que les fibres optiques, le verre optique et les semi-conducteurs.
Granulométrie (#) : Conforme à la norme japonaise JIS (largement utilisée en Chine). Plus le numéro de maille est élevé, plus la granulométrie est fine et plus la surface polie est lisse.
Fiber Lapping Oil: A blended fluid with green silicon carbide micropowder dispersed in oil-based or water-based medium. It is matched with fiber lapping machines to remove scratches, trim end faces and achieve high-precision polishing.
2. Key Parameters of 4000# / 6000# / 8000# (JIS Standard)
| Specification (JIS#) | Median Particle Size D50 (μm) | Maximum Particle Size D94 (μm) | Fiber Lapping Process | Core Function |
|---|---|---|---|---|
| 4000# | 3.0 ± 0.4 | ≤ 4.0 | Fine Lapping / Semi-Fine Polishing | Remove residual scratches from 9/1μm lapping films and level fiber end faces |
| 6000# | 1.5 ± 0.3 | ≤ 2.5 | Precision Lapping / Pre-Polishing | Conduct in-depth finishing, eliminate micro scratches and reduce surface roughness |
| 8000# | 0.8 ± 0.2 | ≤ 1.5 | Ultra-Fine Polishing / Final Polishing | Achieve mirror-grade finishing with Ra ≤ 0.01μm, scratch-free and pit-free surface |
3. Model Selection & Matching in Fiber Lapping
Standard 4-Step Lapping Process (Common Combination)
- Coarse Lapping: 30μm / 15μm – Remove adhesive burrs and fix end face angles
- Medium Lapping: 9μm / 6μm – Fast material removal and primary surface leveling
- Fine Lapping: 3μm / 1μm or 4000# Green SiC – Transitional finishing and coarse scratch elimination
- Precision & Final Polishing: 6000# to 8000# Green SiC or cerium oxide – Achieve defect-free mirror finishing
Selection Recommendations
- 4000#: Universal fine lapping grade, cost-effective for most SC/LC/FC fiber jumpers
- 6000#: High-end precision lapping grade, ideal for polarization-maintaining fibers, high-power fibers and low-reflection application scenarios
- 8000#: Premium final polishing grade, designed for telecom-grade optical fibers, medical optical fibers and applications requiring ultra-high surface finish
4. Key Purchasing Criteria (Fiber-Grade)
- Purity: SiC content ≥ 99.0%, magnetic impurities ≤ 0.001% to prevent fiber surface scratches
- Particle Size: Compliant with JIS standards with accurate D50 value and narrow particle size distribution (no oversized particles)
- Dispersibility: No precipitation or agglomeration in lapping fluid to ensure uniform polishing performance
- Particle Morphology: Equiaxed or spherical particles to avoid deep micro scratches
5. Common Misconceptions
❌ Green SiC ≠ Black SiC: Black silicon carbide boasts high toughness but low purity, which causes severe scratches and is inapplicable for fiber precision polishing.
❌ Finer grain does not mean better performance: 8000# features low processing efficiency; 4000# combined with 6000# fully meets the demand for commercial standard fiber jumpers.
❌ Standard mixing is prohibited: JIS mesh standard is different from FEPA (F#) standard; JIS standard must be confirmed during procurement.
6. Summary
- 4000#: Core grade for fine lapping with stable and efficient performance
- 6000#: Upgraded quality grade, the mainstream material for precision finishing
- 8000# : Grade de polissage haut de gamme pour une finition de surface optimale
