Black Silicon Carbide (SiC) for Quartz Cutting
Black silicon carbide (SiC) is a widely used abrasive material in the cutting and grinding of quartz due to its high hardness, thermal stability, and cost-effectiveness. Below is a detailed guide on its properties, applications, and best practices for quartz cutting.
1. Why Use Black SiC for Quartz Cutting?
Key Advantages:
High Hardness (Mohs ~9.5) – Harder than quartz (Mohs 7), ensuring efficient material removal.
Sharp & Brittle Grains – Fractures during cutting, exposing fresh sharp edges for continuous abrasion.
Thermal Resistance – Withstands high temperatures generated during cutting without degrading.
Cost-Effective – Cheaper than diamond or green SiC, making it ideal for general quartz cutting.
Limitations:
Lower Purity (~97-98%) than green SiC (99%+), which may introduce minor impurities.
Faster Wear than diamond, requiring more frequent replacement in high-precision applications.
2. Applications in Quartz Cutting
Common Uses:
Loose Abrasive Cutting (Slurry Sawing)
Mixed with water or oil to form a slurry for wire saws or gang saws.
Typical grit sizes: #80–#220 (coarse cutting), #240–#600 (fine finishing).
Bonded Abrasive Tools (Grinding Wheels & Blades)
Resin-bonded or vitrified SiC wheels for quartz slab cutting.
Used in CNC machines, lapidary saws, and manual cutting tools.
Lapping & Polishing
Finer grits (#800–#2000) for smoothing quartz surfaces before polishing.
3. Recommended Grit Sizes for Quartz Cutting
| Application | Grit Size (FEPA) | Particle Size (µm) | Surface Finish |
|---|---|---|---|
| Rough Cutting | #60 – #120 | 250 – 125 | Coarse, fast cut |
| Medium Finishing | #150 – #240 | 100 – 53 | Smoother edges |
| Fine Grinding/Lapping | #320 – #600 | 46 – 20 | Near-polished |
| Polishing Prep | #800 – #1200 | 15 – 5 | Very smooth |
Cutting Parameters:
Speed: Moderate (too high can cause overheating).
Coolant: Water-based or oil-based coolant to prevent thermal cracking.
Pressure: Controlled feed rate to avoid chipping.
Safety & Handling:
Dust Control: SiC dust is harmful—use wet cutting or proper ventilation.
Tool Maintenance: Check wear regularly; replace bonded wheels when efficiency drops.