Alumina Ceramic Insulators and High-voltage Alumina Ceramic Insulating Parts

Alumina ceramic insulators are made of high-purity alumina (Al₂O₃, typically 95% to 99%). They are used to support and secure live conductors and insulate them from ground or other conductors at different potentials.

Alumina ceramic insulators are manufactured through dry pressing, isostatic pressing, or injection molding, followed by sintering at temperatures exceeding 1600°C. They come in a variety of shapes and sizes, ranging from electronic components measuring a few millimeters to insulators for high-voltage transmission towers several meters tall. They are one of the most fundamental, critical, and widely used insulating components in the power, electronics, and high-voltage sectors.

The material properties of alumina ceramic perfectly match the demanding requirements of insulators:

1. Excellent Electrical Insulation - Its Core Advantage

• Its extremely high volume resistivity at room temperature (>10¹⁴ Ω·cm) makes it an excellent insulator.
• Stable High-Frequency Performance: The dielectric constant and dissipation factor remain stable at high frequencies, making it suitable for high-frequency and high-voltage environments.

2. Extremely High Mechanical Strength

• Its compressive strength is exceptionally high (>2000 MPa), capable of withstanding significant mechanical loads such as conductor tension, wind, and ice loads.
• Its excellent flexural strength provides a solid support for equipment.

3. Excellent High-Temperature and Thermal Shock Resistance

• It can withstand long-term operating temperatures up to 1500°C without burning or aging.
• Its low coefficient of thermal expansion allows it to withstand extreme temperature fluctuations without cracking (such as cold water droplets splashing onto high-temperature insulators during rainy weather).

4. Excellent Weather and Corrosion Resistance

• It withstands the effects of sun and rain, acids, alkalis, salt spray, and ozone, remains rust-free, and has an extremely long service life.
• It performs far better than glass or composite insulation materials in harsh environments such as coastal areas and industrial pollution.

5. High Hardness and Abrasion Resistance

• It has a surface hardness of up to 9 on the Mohs scale, making it resistant to scratches from sand, dust, and other debris, maintaining a smooth, clean surface.

Alumina ceramic insulators are a cornerstone of the energy and electronics industries, with ubiquitous applications:

1. Power Transmission and Distribution Systems (Core Application)

• High-voltage/UHV transmission lines: Disc suspension insulator strings are the sole insulating link between the tower and the conductors, bearing enormous mechanical and electrical loads.
• Substations: Post insulators support and insulate busbars, disconnectors, and other equipment. Bushing insulators are used for lead-out wires in transformers and other equipment.

2. Electrified Railways

• Used for supporting and insulating railway catenary systems, ensuring safe power supply for electric locomotives.

3. Electronic and Communications Equipment (High-Frequency and High-Voltage Applications)

• Alumina ceramics not only provide insulation but also often serve as functional substrates.
• Microwave and Radio Frequency Equipment: Used as insulating supports and windows in waveguides, antennas, and radar systems. 
• Lasers and Vacuum Electronic Devices: Used for discharge tubes and electrode supports in CO₂ laser tubes; used for internal insulation in X-ray tubes, vacuum capacitors, particle accelerators, and other equipment.
• High-Voltage Power Supplies and Pulsed Power Equipment: Used to isolate electrodes with different potentials in high-voltage generators and Marx generators. They require extremely high dielectric strength and pulse shock resistance.
  

4. Industrial Equipment

• Electric Furnaces and Heating Equipment: Used for supporting and insulating heating elements, ensuring they withstand the high temperatures within the furnace.
• High-Voltage Switchgear: Serves as insulating support for busbars and switches.
• New Energy Equipment: Internal insulation and support for photovoltaic inverters, and insulating components in converters for wind turbine systems.

5. New Energy Vehicles

• Provides insulation and support between high-voltage circuits in charging stations, battery packs, and motor controllers.

6. Other Special Applications

• Highly Polluted and High-Humidity Environments: Use pollution-resistant alumina insulators (e.g., using large and small sheds to increase creepage distance) in heavily polluted, salt-fog, and high-humidity environments, such as coastal areas, chemical plants, and coal mines.
• Aerospace and Defense: Used for high-reliability circuit insulation in systems such as spacecraft, missiles, and radars, requiring lightweight and extremely reliable performance.