High-purity Alumina Ceramic Bushings 95%-99.9% Alumina Ceramic Flange Bushings

Alumina ceramic bushings are hollow cylindrical components made from high-purity alumina (Al₂O₃, commonly 95% or 99% pure) ceramic material. They are formed by dry pressing, isostatic pressing, or extrusion, followed by sintering at temperatures exceeding 1600°C.

Their core function is to be embedded or assembled into cavities in mechanical equipment, providing wear resistance, insulation, corrosion resistance, and guidance, thereby protecting more expensive core equipment (such as equipment housings and brackets) from wear and electrochemical corrosion.

The advantages of alumina ceramic bushings stem directly from their material properties, making them a perfect alternative to metal or plastic bushings under specific operating conditions:

1. Extremely high hardness and exceptional wear resistance. They are extremely resistant to high-speed erosion and abrasive wear from materials, dust, and fibers, resulting in a service life dozens of times longer than metal bushings, significantly reducing downtime and replacement frequency.
2. Excellent electrical insulation. They are an excellent insulator with a high volume resistivity. Used in applications requiring current isolation to prevent electrochemical corrosion or short circuits, ensuring equipment and personnel safety.
3. Excellent chemical resistance. Suitable for use in humid and corrosive environments (such as chemical, electroplating, and marine environments), where metal bushings would rapidly corrode and fail.
4. Low friction coefficient and smooth surface. Can be polished to a very smooth surface with a low coefficient of friction, reducing frictional resistance and energy loss with rotating shafts or reciprocating rods, resulting in smoother operation and reduced wear on mating parts.
5. High temperature resistance. Long-term operating temperatures up to 1500°C, with excellent thermal stability, allow for use in high-temperature environments, where plastic bushings would soften and melt.

Alumina ceramic bushings are experts in solving wear, corrosion, and insulation problems and are commonly used in the following areas:
1. Mining, power generation, and steel mill equipment (core wear-resistant applications)

• Applications: Crusher, vibrating screen, feeder, chute, fan shaft sleeve, and dust removal system.
• Purpose: Protects mounting holes in equipment from high-speed erosion caused by materials containing hard particles (ore, coal dust, slag). For example, a bushing installed in the wall of an equipment allows a shaft to pass through it. If worn, only the inexpensive bushing needs to be replaced, not the expensive wall.

2. Chemical, Electroplating, and Environmental Protection Equipment (Corrosion-Resistant Core Applications)

• Applications: Pumps, valves, agitators, electroplating tanks, and wastewater treatment equipment.
• Purpose: As a bearing sleeve or guide sleeve, it provides long-term wear and corrosion resistance in strong acid, alkali, and salt spray environments, without the pitting or intergranular corrosion that can occur with stainless steel.

3. Electrical and Automation Equipment (Insulation Core Applications)

• Applications: High-voltage switchgear, vacuum circuit breakers, insulators, robotic arms, and linear modules.
• Purpose: Provides insulating support and positioning for moving or fixed shafts, preventing the passage of current while ensuring precise movement.

4. Textile and Papermaking Machinery

• Applications: Wire guides, guide roller bearing sleeves, and pulp pumps.
• Purpose: Its smooth, wear-resistant surface prevents snagging or abrasion of sensitive yarn and paper fibers.

5. High-Temperature Equipment

• Applications: Kiln car bearing sleeves, high-temperature furnace guide sleeves.
• Purpose: Provides support and guidance for moving parts in high-temperature environments, preventing failure due to high temperatures.