What are the main uses of alumina ceramics?

High purity alumina, as a new type of high purity material, its role is increasingly expanding. High purity alumina is a white micro powder with uniform particle size, easy dispersion, stable chemical properties, moderate high-temperature shrinkage performance, and good sintering performance conversion rate. It is a basic raw material for producing heat resistant, wear-resistant, and corrosion-resistant products. The use of high-purity alumina also lies in many aspects such as its use in transparent alumina sintered bodies, carriers for fluorescent materials, additives for special gases, etc. Its application range can be said to be very wide.

Application of Sapphire

Sapphire is a type of alumina（ α- A single crystal of Al2O3, also known as corundum. Sapphire, as an important technological crystal, has been widely used in many fields such as science and technology, national defense, and civil industry.

Sapphire crystal has excellent optical properties, mechanical properties, and chemical stability, high strength, high hardness, and resistance to erosion. It can work under harsh conditions near 2000 ℃ high temperature. Sapphire crystal has a unique lattice structure, excellent mechanical properties, and good thermal properties.

The main uses of sapphire crystals:

Widely used as window materials for infrared military devices, satellite space technology, and high-intensity lasers. It has become the most ideal substrate material for practical applications such as semiconductor GaN/Al2O3 light-emitting diodes (LEDs), large-scale integrated circuit SOI and SOS, and superconducting nanostructured thin films.

2. Used in the semiconductor lighting industry, such as LED, which is a new generation of light sources and is recognized as the most promising high-tech field in the 21st century. LED can increase the luminous efficiency by nearly 10 times, and its lifespan is more than 20 times that of traditional lamps. It also has advantages such as green and environmental protection. Currently, major countries and regions around the world have formulated LED technology and industry development plans, but there are only two substrates available for commercialization of LED production, namely sapphire and silicon carbide substrates. Currently, 80% of LED enterprises worldwide use sapphire as a substrate for commercialization production, so sapphire has huge market application prospects.

Used in civil aerospace, military industry, etc., such as transparent windows, fairing, photoelectric windows, protective plates, gyroscopes, wear-resistant bearings, and other components. Military optoelectronic equipment, such as optoelectronic pods, optoelectronic trackers, infrared warning systems, submarine optoelectronic masts, etc.

4 The application of sapphire crystal in the civil field, such as the scanning window of bar code scanner, the surface mask of never wear radar watch, the fiber guide in Textile manufacturing, the camera lens, and wear-resistant bearings.

From a functional perspective, high-purity alumina has various functions such as electricity, optics, chemistry, biology, sound absorption, thermodynamics, mechanics, etc. Its main application fields are as follows:

1. Electrical base materials: integrated circuit substrates, packaging, spark plugs, Na-S battery solid electrolytes. (Using 4N high-purity nano alumina granulation powder, VK-L05C)

2. Optical functions: high-pressure sodium vapor lamp light emitting tube, laser material, sensor. (Using 5N high-purity nano alumina VK-L100G)

3 chemical functions: controlling chemical reactions, purifying exhaust gases, catalyst carriers, corrosion-resistant materials, and solid enzyme carriers.

4 biological functions: artificial bones, artificial tooth roots, (using 5N high-purity nano alumina VK-L100G)

5. Thermal function: heat-resistant, heat-insulating structural materials

6 Mechanical functions: grinding materials, cutting materials, bearings, precision mechanical components.

3. Application of high-purity nano alumina fine ceramics: Nano alumina fine ceramics made from nano alumina as the main raw material have been applied in the field of high-tech and many industries due to their multiple functions:

Application of 1 in the electronic industry

(1) Ceramic multilayer substrates for multi chip packaging: There are four manufacturing methods for nano alumina ceramic multilayer substrates used in packaging, including thick film printing, green lamination, green printing, and thick film mixing.

(2) High pressure sodium lamp light emitting tube: A transparent nano alumina body formed from polycrystalline opaque high-purity nano alumina (VK-L100G, 99.999%), applied to high pressure sodium lamp light emitting tubes, with a lighting efficiency twice that of mercury lamps, thus opening up new ways to improve lighting efficiency. Transparent and high-purity nano alumina fine ceramics not only transmit light, but also have properties such as high temperature resistance, corrosion resistance, high insulation, high strength, and low dielectric loss. They are excellent optical ceramics and can also be used as microwave oven windows.

(3) Nano alumina ceramic sensor: Using the structural characteristics and characteristics of high-purity nano alumina (VK-L100G) ceramics such as grains, grain boundaries, and pores as sensitive components, it is used in high-temperature and corrosive gas containing environments to ensure accurate and rapid detection and control of information. From the type of application, there are sensors such as temperature, gas, and temperature.

2 Bio nano high purity alumina (VK-L100G) ceramics

The use of high-purity alumina polycrystals as biological functional materials in the human body began in 1969. There are two types of high-purity alumina fine ceramics used in medical engineering: single crystals and sintered polycrystals. At present, the United States, West Germany, Switzerland and the Netherlands are widely using polycrystalline high-purity nano alumina to produce artificial teeth and artificial bones. The medical materials are mainly high-purity nano alumina, which is used for tooth roots and joints. The contact angle between nano alumina fine ceramics and human Interstitial fluid is the material closest to human teeth. So far, there are more than 20 types of bioceramics used in medical engineering, with high-purity nano alumina being the most commonly used one.

3 nanometer alumina (VK-L05C) ceramic tool

The hardness (Hr) of nano alumina is 2700-3000, and the Young's modulus (kg/mm2) is 35000-41000. Thermal conductivity coefficient 0.75~1.35 × 103J/m · h · ℃, thermal expansion coefficient 8.5 × 10-6/℃ (room temperature~1000 ℃). While making use of these characteristics, people have also developed Al2O3-TiO2, Al2O3-ZrO2 series ceramics to improve the toughness and thermal shock resistance of nano alumina ceramic tools. The control of grain size of nano alumina in the sintering process of Al2O3 particle size composition is an important link to determine the quality of tools. If high-temperature isostatic pressing (HIP) sintering is adopted, the grain size can be 0.3~0.5 microns. The bending strength of nano alumina cutting tools can be increased to 900~1000MPa, which is suitable for high-speed cutting needs.

As can be seen from the above, high-purity alumina, as a new type of high-purity material, has developed particularly rapidly in recent years and has become more widely used.

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