1. What is Green Silicon Carbide Micropowder?
Green silicon carbide is a synthetic abrasive produced in an electric resistance furnace from a high-purity mix of silica sand and petroleum coke, with salt as a catalyst. The “green” variety is of higher purity and has slightly sharper and harder crystals than its black silicon carbide counterpart.
“Micropowder” refers to the finely crushed and precisely graded form of this abrasive, typically with particle sizes measured in microns (µm). These powders are suspended in liquids (water or oil) to create polishing slurries.
2. Key Properties & Why It’s Excellent for Polishing
Extreme Hardness: With a Mohs hardness of 9.2-9.3, it is one of the hardest materials available. This allows it to effectively cut hard materials.
Sharp & Brittle Crystals: The grains fracture easily under pressure, creating new sharp edges. This self-sharpening property ensures consistent cutting action and prevents dulling.
High Thermal Conductivity: Helps dissipate heat generated during the polishing process, reducing the risk of thermal damage to the workpiece.
Chemical Inertness: It is resistant to acids and alkalis, meaning it won’t react with and contaminate the polishing slurry or the workpiece.
| chemical composition | physical properties | ||
| SiC | ≥99% | Density | ≥3.18g/cm3 |
| F.C | ≤0.20% | mohs hardness | 9.5 |
| Fe2O3 | ≤0.40% | smelting point | 2250℃ |
| SiO2 | ≤0.05% | Magnetic | ≤0.017% |
3. Primary Applications in Polishing
Green SiC micropowder is ideal for polishing hard, non-metallic materials where surface contamination (like iron) is a concern. Key applications include:
Ceramic Substrates: As you mentioned, it’s widely used for polishing Alumina (Al₂O₃) and Aluminum Nitride (AlN) substrates used in electronics (LEDs, power modules).
Technical Ceramics: Polishing components made from silicon carbide (SiC), zirconia (ZrO₂), and other advanced ceramics for industrial and medical use.
Glass & Optics: Fine grinding and pre-polishing of optical glass, lenses, and CRT glass.
Semiconductor Wafers: While not for the final CMP stage, it’s used for back-grinding and initial shaping of silicon wafers.
Hard Metal & Alloys: Polishing carbide tools, titanium alloys, and other difficult-to-grind metals.
Stone & Jewelry: Polishing hard gemstones like agate, jade, and marble.