A new generation of hard material alumina

As an important chemical material, spherical alumina has a series of excellent properties such as high hardness, high strength, corrosion resistance and high temperature resistance. Spherical alumina has the above-mentioned properties and is widely used in ceramic materials, chemical mechanical polishing abrasives, catalysts and catalyst supports due to its size and morphology. Broadly speaking, alumina can be divided into two categories: hydrated alumina and anhydrous alumina.

 Alumina water

The hydrated alumina is also called hydrated alumina, and six types of hydrated alumina have been identified. Alumina trihydrate, including industrial aluminum hydroxide (α-Al2 O 3•H 2 O), diaspore (β1 -Al 2 O 3•H 2 O) and boraxite (β2 -Al 2 O 3•H 2 O): Alumina monohydrate, including boehmite (α)-Al 2 O 3•H 2 O), gibbsite (β -Al 2 O 3•H 2 O): pseudo-boehmite (Al 2 O 3•1.3-2.2H 2 O).

Anhydrous alumina

At present, there are at least eight different crystal forms of alumina: ρ- (amorphous), χ- (amorphous), η- (cubic system), γ- (cubic system), θ- (monoclinic crystal) (), δ-(tetragonal), κ-(hexagonal) and α-(hexagonal) alumina. They are all isomers, in which α-Al2 O 3 is the thermally stable phase after high-temperature heat treatment, and the other is the unstable transition state alumina. Generally, for various crystal forms of alumina, their chemical and physical properties are very different, such as density, pore structure, specific surface area, thermal stability and so on. When using different preparation methods to prepare alumina, even if it is the same crystal form, its properties are very different.

 X-, ρ-Al2 O 3: belongs to amorphous alumina, which is the product of rapid dehydration and quenching of the precursor. It is usually called "Fast Powder", and it is called FCA (Fast Calcined Alumina) in foreign countries. It has strong hydration and water absorption, and is often used as an adhesive and water absorbent. It has been widely used in many fields.

η-Al2O3: The precursor product dehydrated at low temperature usually has a large specific surface area, but has poor thermal stability and is easy to crystallize at high temperature.

γ-Al2O3: It has strong adsorption capacity and catalytic activity and is called activated alumina. Generally, the specific surface area is large, the bulk density is small, the special pore structure is obtained, the thermal stability and mechanical strength are good, and its performance is easy to change, so the application field is very wide.

θ-, δ-, κ-Al2O3: The precursor product dehydrated at a temperature above 600 ℃, almost contains no structural water, its specific surface area and pore volume are usually small, but its thermal stability is good, and it can Use a catalytic support for high-temperature reactions.

α-Al2 O 3: Also known as corundum, it is the final thermally stable crystalline form of transitional alumina after dehydration. It is the most widely used type of alumina crystal, and the crystal does not contain water at all. The structure is compact, the specific surface area is usually small, the melting point is as high as 2050°C, and it has high hardness, high strength, wear resistance and corrosion resistance. It is usually used for abrasives, high temperature resistant materials and ceramic composite materials.

 The crystal transition of alumina

The aluminaaqueous solution is calcined at different temperatures to continuously remove the water in the structure, and the spatial arrangement of aluminum atoms and oxygen atoms is also constantly changing. Alumina changes from an amorphous state to a crystalline state, and gradually forms various unstable transition state aluminas. . When the temperature exceeds 1200°C, a lattice remodeling phase transition occurs, and the arrangement of oxygen atoms is transformed into a hexagonal close-packed structure, thereby forming a thermally stable phase α-Al2O3.

Overview of alumina Al2O3 powder

Alumina is an inorganic substance with the chemical formula Al2O3. It is a high-hardness compound, also known as bauxite in mining, ceramics and materials science. It is a white solid, insoluble in water, odorless, tasteless, and very hard in nature. Alumina is a typical amphoteric oxide (corundum is alpha-shaped and belongs to the hexagonal compound with the highest density. It is an inert compound that is slightly soluble in acid [1 ] Soluble in inorganic acids and alkaline solutions, almost insoluble in water and non-polar organic solvents; relative density (d204) 4.0; melting point 2050°C, boiling point 2980°C, ionized ionic crystals at high temperature, commonly used in the manufacture of refractory material.

Industrial alumina is prepared from bauxite (Al2O3•3H2O) and gibbsite. For Al2O3, which requires high purity, it is usually prepared by chemical methods. There are many kinds of Al2O3 crystals, and there are more than ten kinds of known crystals. α-Al2O3, β-Al2O3 and γ-Al2O33 crystal types are different in structure and performance. They are almost completely transformed into α-Al2O3 at high temperatures above 1300℃.

The characteristics of spherical alumina Al2O3 powder: high bulk density: large particle size, wide particle size distribution, high density accumulation of rubber and plastic can be realized, low viscosity, good fluidity compound; high thermal conductivity: phase with crystalline silicon A relatively high packing density can make the thermal conductivity and heat dissipation rate of the composite material higher;

Low abrasiveness: Due to the spherical shape, the kneader, molding machine and mold wear less.

Alumina is used to fuse high-quality bauxite to produce brown corundum, while high-quality aluminate is used to produce powdered corundum and white corundum. Their natural crystal structure makes them hard and fast. Raw materials for bonding abrasives and coated abrasives. Alumina can be recycled multiple times, and the number of cycles depends on the grade of material and the specific process. Most standard sandblasting equipment can be used.

Spherical alumina Al2O3 powder should be stored in a dry, cool and sealed environment, and should not be exposed to the air. In addition, avoid heavy pressure and transport it as a normal item. Packed in a double-layer plastic bag, it can be filled with argon in a vacuum, or it can be evacuated and filled with argon for protection. Vacuum packing 100G, 500G or 1KG/bag, 25kg/drum or according to your requirements.

Alumina Al2O3 powder application

1. Paint: enamel paint, wear-resistant paint and plasma spraying.

2. Ceramics: transparent ceramics, bio-ceramics and alumina ceramics.

3. Petrochemical products: high-efficiency catalysts, catalyst carriers and automotive exhaust purification materials.

4. Polishing materials: sub-micron/nano-level abrasive materials, monocrystalline silicon wafer polishing, precision polishing materials.

5. Illumination: Long afterglow phosphor raw material and rare earth tricolor phosphor raw material high pressure sodium tube, LED lamp, etc.

6. Electronic products: integrated circuit substrates, single crystal materials and far-infrared materials.

7. Cosmetics: cosmetic fillers.

8. Inorganic membrane materials.

Alumina is suitable for various wet and dry processes. It can finely grind the rough surface of any workpiece. It is one of the most economical abrasives. The hardness of this sharp water chestnut synthetic abrasive is second only to diamond, and it is especially suitable for occasions with strict requirements for iron pollution. For the roughest cutting, it can also be made into a pebble shape to process precision-sized workpieces to achieve extremely low roughness. The diamond structure is one of the abrasives with the fastest cutting speed.

Alumina Al2O3 powder price

The price of spherical alumina Al2O3 powder will vary randomly with production cost, transportation cost, international situation, exchange rate and market supply and demand of spherical alumina Al2O3 powder. Tanki New Materials Co.,Ltd. aims to help all industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full set of customized services. If you are looking for spherical alumina Al2O3 powder, please feel free to send an inquiry to get the latest price of spherical alumina Al2O3 powder.

Suppliers of alumina Al2O3 powder

As a global supplier of spherical alumina Al2O3 powder, Tanki New Materials Co.Ltd has extensive experience in advanced, engineered material performance, application and cost-effective manufacturing. The company has successfully developed a series of powder materials (including boron carbide, aluminum carbide, titanium carbide, etc.), high-purity targets, functional ceramics and structural devices, and provides OEM services.