White fused aluminum oxide polishing powder

What is White Fused Aluminum Oxide Polishing Powder?

White Fused Aluminum Oxide (WFAA) polishing powder is a high-purity, synthetic abrasive material. It is produced by fusing calcined alumina (Al₂O₃) in an electric arc furnace at temperatures above 2000°C, followed by controlled crushing, milling, and precision grading into fine or ultra-fine powders.

• Primary Composition: >99% α-Al₂O₃ (corundum crystal structure).

• Key Property: Exceptional hardness (9.0 on the Mohs scale).

2. Key Characteristics & Advantages

• High Hardness & Sharpness: Provides efficient material removal and generates a fine, consistent scratch pattern, leading to a superior surface finish.

• High Chemical Purity (>99% Al₂O₃): Contains minimal metallic impurities (e.g., iron oxide). This makes it non-contaminating and ideal for applications where staining or chemical reaction is unacceptable.

• Friability: The grains have a self-sharpening characteristic. They fracture into smaller, sharp fragments under pressure, maintaining cutting efficiency and preventing dulling.

• Chemical Inertness: Highly stable and resistant to acids and alkalis, ensuring it does not react with workpiece materials or polishing fluids.

• Thermal Stability: Maintains its structure and hardness at high temperatures generated during polishing.

3. Manufacturing Process

1. Fusion: High-purity calcined alumina is melted in an electric arc furnace.

2. Cooling & Ingot Formation: The molten mass is cooled slowly to form large ingots of solid, crystalline alumina.

3. Crushing & Milling: The ingots are crushed, ball-milled, or jet-milled into a coarse powder.

4. Classification & Grading: The powder undergoes rigorous sizing processes (e.g., air classification, sedimentation) to separate it into very specific, narrow particle size distributions (often from coarse grits down to micron or sub-micron levels for polishing).

5. Treatment: May be washed with acid to remove any residual surface impurities.

4. Primary Applications

WFAA polishing powder is the go-to abrasive for finishing hard, high-value materials where surface integrity and purity are paramount.

• Optical & Precision Lenses: Polishing of glass, crystals, optical elements, and lenses due to its purity and ability to achieve excellent clarity and low surface roughness.

• Semiconductor & Wafer Processing: Critical for silicon wafer back-grinding, sapphire substrate polishing, and other processes requiring contamination-free abrasion.

• Technical Ceramics: Finishing of alumina, zirconia, silicon carbide, and other advanced ceramics used in medical, aerospace, and industrial components.

• Metal Polishing: Used for stainless steel, titanium, hardened steel, and other alloys to achieve a high-luster, flawless finish without embedding impurities.

• Stone & Gem Polishing: Final polishing stage for granite, marble, and precious gemstones like sapphires and rubies.

• High-End Wood Finishing: Used in some sealed wood coatings for burnishing.

White Fused Aluminum Oxide Polishing Powder is a high-purity, high-performance synthetic abrasive prized for its hardness, sharpness, and chemical cleanliness. It is the premier choice for precision polishing of optics, semiconductors, technical ceramics, and high-grade metals, where achieving a flawless, contaminant-free surface is the primary goal. Its key advantage lies in providing aggressive yet controllable cutting action while maintaining exceptional workpiece purity.