White corundum electrically fused in arc furnace with high grade processed alumina as raw material. It has higher hardness and slight lower toughness It is also characterized by its high purity, ability of self-sharpening, better cutting, less heat emit, higher efficiency.
| chemical composition（typical value） | physical properties(typical value) | ||
| Al2O3 | ≥99.5% | specific gravity | ≥3.90g/cm3 |
| Na2O | ≤0.35% | hardness（mohs） | 9.0 |
| Fe2O3 | ≤0.06% | bulk density | 1.75-1.95g/cm3 |
| SiO2 | ≤0.05% | smelting point | 2250℃ |
| CaO | ≤0.05% | refractoriness temperature | 2100℃ |
| MgO | ≤0.03% | ||
| K2O | ≤0.02% | ||
| LOI | ≤0.10% | ||
White corundum is a material with high hardness and high wear resistance, and is often used in wear-resistant coatings.
White corundum Applications:
1. Industrial equipment: used for coatings of easily worn parts such as pumps, valves, and pipes to extend service life.
2. Aerospace: used for protection of high-temperature and high-speed parts such as aircraft engines and turbine blades.
3. Automobile industry: used for wear-resistant coatings of engine cylinders, pistons and other parts.
4. Mining machinery: used for wear-resistant protection of equipment such as crushers and conveyor belts.
5. Chemical equipment: used for coatings of corrosion-resistant and wear-resistant parts such as reactors and agitators.
White corundum Advantages
1. High hardness: Mohs hardness reaches 9, second only to diamond, and has excellent wear resistance.
2. High temperature resistance: high melting point, suitable for high temperature environment.
3. Chemical stability: acid and alkali corrosion resistance, suitable for harsh environment.
4. Strong adhesion: firmly bonded to the substrate, not easy to fall off.
5. Long life: significantly extend the service life of equipment and reduce maintenance costs.
Preparation method
1. Thermal spraying: Melt white corundum powder and spray it onto the substrate by flame or plasma spraying.
2. Cold spraying: Spray at high speed at low temperature to reduce thermal stress.
3. Electroplating: Deposit white corundum coating on the substrate surface by electrochemical method.
Precautions
1. Substrate treatment: Clean and roughen before spraying to ensure adhesion.
2. Process control: Strictly control spraying parameters to ensure coating quality.
3. Post-processing: Heat treatment or mechanical processing is required after spraying to improve performance.