Alpha-alumina has stable chemical properties, corrosion resistance, high hardness, good insulation properties, high melting point and high toughness, and is used in different fields.
Application of α-alumina powder in ceramics
Microcrystalline alumina ceramics is a new type of ceramic material with uniform and dense structure and nano or sub-micron grain size. It has the advantages of high mechanical strength, wear resistance, corrosion resistance, oxidation resistance, adjustable expansion coefficient and good thermal stability. Its main feature is that the primary crystal is small. Therefore, the most important technical condition for the preparation of microcrystalline alumina ceramics is to prepare α-Al2O3 powder with small original crystal and high sintering activity. This α-Al2O3 powder can become a dense ceramic body at a relatively low sintering temperature.
Application of α-alumina powder in refractory material
α-Al2O3 powder is different in refractory materials according to the application, and the powder requirements are also different. For example, if you want to speed up the densification of refractory materials, nano-alumina is the best choice; if you want to prepare shaped refractories, you need α-Al2O3 powder with coarse grains, small shrinkage, and strong deformation resistance. Flake or plate-shaped crystallites are better; but if it is an amorphous refractory material, α-Al2O3 is required to have good fluidity, high sintering activity, and the particle size distribution requires the largest bulk density, and fine-grained crystallites are better.
Application of α-alumina powder in polishing materials
Different polishing applications require different materials. Products for rough polishing and intermediate polishing require strong cutting force and high hardness, so their microstructure and crystals are required to be coarse; α-alumina powder for fine polishing requires that the polished product has low surface roughness and high gloss Therefore, the smaller the primary crystal of α-Al2O3, the better.
Application of α-alumina powder in filler material
In the filling material, in order to ensure that it combines well with organic matter and reduce the impact on the viscosity of the system, the most basic requirement for α-Al2O3 is that the fluidity is good enough, preferably spherical, because the higher the sphericity, the surface. The smaller the energy, the better the surface fluidity of the ball; secondly, the α-Al2O3 powder with complete crystal development, high chemical purity and high true specific gravity has better thermal conductivity and better effect when used for insulating and thermally conductive materials.
Application of α-alumina powder in capacitor corundum material
In industry, pure α-alumina powder is often sintered in a high-temperature electric furnace to make artificial corundum, also known as fused corundum. This material has the characteristics of high hardness, clear edges and corners, and the microstructure is preferably near spherical. In the process of high-speed grinding, the abrasive grains have strong cutting force, and the abrasive grains are not easy to break.thereby increasing its service life.