WA White Fused Alumina Lapping Powder

WA White Fused Alumina (WFA) Lapping Powder is a high-purity abrasive material widely used for precision grinding, polishing, and lapping applications. Here’s a detailed breakdown of its properties, applications, and key considerations:

1. Composition & Properties

• Chemical Formula: α-Al₂O₃ (≥99.5% purity).

• Color: White (vs. brown fused alumina, which contains impurities like Fe₂O₃).

• Hardness: Mohs 9 (second only to diamond and silicon carbide).

• Melting Point: ~2050°C.

• Grit Sizes: Ranges from coarse (F12-F220) for rough lapping to fine (F600-F2000) for mirror finishes.

• Shape: Angular or semi-rounded particles (affects aggressiveness in material removal).

2. Key Advantages for Lapping

• High Cutting Efficiency: Sharp edges enable fast material removal (e.g., on metals, ceramics, or glass).

• Consistent Particle Size: Tight particle distribution ensures uniform surface finish.

• Low Contamination: Minimal iron or silica content prevents workpiece staining.

• Thermal Stability: Resists heat buildup during high-speed lapping.

3. Typical Applications

Materials Processed:

• Metals: Stainless steel, titanium, hardened steel.

• Ceramics: Alumina, zirconia, silicon nitride.

• Optics: Glass lenses, sapphire substrates.

• Semiconductors: Silicon wafers, IC components.

Processes:

• Lapping: Flatness correction (e.g., valve seats, gauge blocks).

• Polishing: Achieving Ra <0.1 μm surface roughness.

• Honing: Precision finishing of cylindrical parts.

4. How to Use WA Lapping Powder

1. Slurry Preparation:

   • Mix powder with water, oil, or glycol-based carriers (e.g., 1:3 to 1:5 abrasive-to-carrier ratio).

   • Additives (e.g., surfactants) improve dispersion.

2. Equipment:

   • Lapping machines (single/double-sided), polishing pads (cast iron, tin, or polyurethane).

3. Parameters:

   • Pressure: 0.5–2 kg/cm².

   • Speed: 20–100 RPM (lower for finer grits).

5. Grit Size Selection Guide