Coated White Fused Alumina

Product Overview

Coated white fused alumina is a premium surface-modified abrasive made from quality white fused alumina or calcined white fused alumina. A functional coating, such as iron oxide, is applied at high temperature. The treatment addresses the relatively low toughness of conventional white fused alumina while retaining hardness and sharpness and improving fracture resistance. Available in red, blue, green and white, it is used in premium resin-bonded and coated abrasives and precision grinding of difficult materials.

Technical Specifications

Key Features

1. High hardness and toughness with improved fracture resistance

Coated white fused alumina retains the sharp cutting edges of α-Al₂O₃ crystals. The coating process eliminates internal microcracks and improves fracture resistance. Compared with conventional white fused alumina, microhardness and toughness can improve approximately 10%, durability 30%-50%, and grinding efficiency 30%.

2. Improved wettability and bonding

Coating creates a rougher surface and greater specific surface area, improving wettability and resin adhesion. In resin-bonded abrasives, this can reduce bond consumption while increasing overall tool strength.

3. Sharp grinding with low heat generation

Strong self-sharpening and grinding action produce sharp-cutting tools that avoid workpiece burns, particularly on heat-sensitive and difficult materials such as stainless steel, hardened steel and high-carbon steel.

4. Multiple grades for different applications

Common grades include RC-WA (red-coated) and CW-WA (white-coated), selected by coating material and color for different workpieces and operating conditions.

Process Overview

Process stage and description

Raw materials: quality white fused alumina or calcined white fused alumina

High-temperature coating: application of a functional surface layer such as iron oxide

Cooling: coating solidification and stabilization

Sizing: classification to F or P standards

Packaging: standard or customized packaging

Available Grit Sizes

Common grits include F24, F30, F36, F46, F54, F60, F80, F100, F120, F150, F180, F220 and F240.

Typical Applications

Premium resin-bonded abrasives: ultra-thin cut-off wheels and grinding discs, particularly for stainless steel, hardened steel, high-speed steel and other difficult materials

Premium coated abrasives: high-speed heavy-duty belts, abrasive cloth and sandpaper

Precision grinding: hardened steel, hard alloys, tool steel and bearing steel

Packaging

Standard bags: 25 kg plastic woven bags with liners

Bulk bags: 1,000 kg per bag (1 ton), plastic woven

Pallet packaging: 25 kg bags stacked on pallets and secured with stretch film

Custom packaging: special packaging on request

Neutral or branded packaging is available on request.

Storage Recommendations

To maintain coated white fused alumina quality during storage, observe the following conditions:

Store in a cool, dry, ventilated warehouse away from direct sunlight. Relative humidity should preferably be ≤60% to prevent caking and mold on packaging.

Stack bags no more than 10 layers high to prevent packaging damage or grain fracture. Use wooden or plastic pallets to keep them off the ground.

Keep separate from acids, alkalis, organic solvents and other corrosive substances. Store different grit sizes separately with clear labels.