The Multifunctional High-Quality Contender - Applications of Spherical Alumina

The Multifunctional High-Quality Contender – Applications of Spherical Alumina

July 30, 2024

Alumina (Al₂O₃) is abundant in nature, widely distributed and part of a vast family with numerous types, making it an indispensable raw material in large-scale industrial production. The requirements for alumina powder materials in various fields are closely related to their shape and particle size. Spherical alumina has become one of the most widely used materials within the alumina family, serving as a core member. Due to its spherical morphology, which results in a relatively larger specific surface area, as well as its high hardness, corrosion resistance, high-temperature resistance, regular shape, uniform size and even dispersion, spherical alumina powder finds broader practical applications.

Here is a detailed introduction:

Grinding and Polishing

Firstly, spherical alumina has high hardness and wear resistance, allowing it to effectively remove surface impurities and oxidation layers during sandblasting and shot peening, thereby reducing the frequency and cost of replacement. Secondly, the regular shape and uniform size of spherical alumina particles ensure even distribution on the workpiece surface during sandblasting, avoiding issues of over-treatment or under-treatment in certain areas, and ensuring consistency in surface treatment. Thirdly, due to its regular shape, spherical alumina has excellent flowability and dispersibility, enabling smooth transportation and spraying in sandblasting equipment, improving work efficiency, and effectively handling complex-shaped workpiece surfaces. Fourthly, spherical alumina exhibits excellent high-temperature and corrosion resistance, maintaining stable performance and effective surface treatment in high-temperature or corrosive environments. Lastly, compared to other irregularly shaped abrasives, the smooth surface of spherical alumina reduces wear and scratching on the workpiece while effectively cleaning its surface, preserving the integrity and aesthetics of the workpiece surface.

3D Printing

Spherical alumina, due to its high strength, high sphericity, and high-temperature resistance, is one of the most commonly used materials in 3D printing. Its excellent particle fluidity, chemical reaction rate, and packing properties make it an ideal printing slurry with high solid content, good fluidity, easy cleaning, and high mechanical performance.

Ceramics

Adding a certain amount of spherical alumina powder during ceramic production significantly alters the ceramic properties. The low-temperature brittleness of ceramics greatly limits their application range; incorporating spherical alumina powder produces low-temperature plastic ceramics. Additionally, spherical alumina significantly enhances ceramic toughness. When the content of spherical alumina powder reaches 5.0%, it effectively improves ceramic toughness and reduces sintering temperature.

Surface Protective Coatings

Using spherical alumina as a coating material is currently a research hotspot. Coating materials protect polymer materials, glass metals, and alloy materials and extend the lifespan of stainless steel products like kitchenware. Due to its high hardness, corrosion resistance, high-temperature resistance, regular shape, uniform size, and even dispersion, spherical alumina is often used as a protective material. It enhances material properties, making them smooth and wear-resistant. As a coating material, spherical alumina powder finds various applications in different environments, offering a simple process and protecting various material surfaces.

Thermal Conductive Fillers

With the advent of the information age, advanced electronic devices are becoming increasingly miniaturized, resulting in a significant increase in the heat they generate, which demands enhanced cooling solutions for the systems. Due to its wide availability in the market, diverse types, lower cost compared to other thermal conductive materials, and high filling capacity in polymer materials, alumina offers high cost-effectiveness. Therefore, most high thermal conductivity insulating materials currently use alumina as the thermal filler. Among the various shapes of alumina, fibrous alumina has the best thermal conductivity but is challenging to industrialize. In contrast, spherical alumina is widely used in thermal conductive filler applications due to its good morphology, high thermal conductivity, thermal expansion coefficient, and simple preparation process.

Another booming market for spherical alumina thermal conductive fillers is electric vehicles (EVs), where systems such as batteries, electronic controls, and motors require thermal interface materials to address thermal runaway issues.Spherical alumina, as a thermal conductive material, is primarily used in thermal interface materials, thermal conductive engineering plastics, thermal conductive aluminum-based copper clad boards, and thermal conductive encapsulation materials. According to QYResearch, thermal interface materials account for 48% of the downstream applications of spherical alumina, thermal conductive engineering plastics account for 17%, and high thermal conductivity aluminum-based copper clad boards account for 14%.

Electronic and Optical Materials

Spherical alumina has extensive applications in the electronic and optical fields. When used as a substrate with rare earth elements as activators, it can produce superior red luminescent materials. The uniform particle size and even dispersion of spherical alumina result in better luminescence performance compared to other shapes of alumina, allowing for optimal determination of the luminescent material’s filling structure. The spherical morphology and reduced particle size decrease the powder’s transparency, improve packing density, reduce transmission light loss, and minimize scattering when spherical alumina is used as a luminescent material, thereby enhancing the brightness of electronic device screens.

Catalysts and Carriers

Due to the large number of unsaturated chemical bonds on the surface of alumina, which provide numerous catalytic active centers, it exhibits high chemical activity. Moreover, spherical alumina has the advantages of low particle wear, long service life, and a large specific surface area. Therefore, catalysts and catalyst carriers made from spherical alumina offer performance that other materials cannot match.In summary, spherical alumina stands out due to its superior properties such as high hardness, corrosion resistance, high-temperature resistance, regular shape, uniform size, and even dispersion. These characteristics make it indispensable in various applications, from grinding and polishing to 3D printing, ceramics, thermal conductive fillers, electronic and optical materials, catalysts, and surface protective coatings. Its versatility and efficiency in enhancing material performance underscore its critical role in industrial production. As technological advancements continue, the demand for spherical alumina is expected to grow, further solidifying its position as a multifunctional, high-quality material.