Application of Nanomaterial Aluminum Oxide in Alumina Ceramics

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Application of Nanomaterial Aluminum Oxide in Alumina Ceramics [Copy link]

【What are nanomaterials? 】 Nanomaterials refer to materials that have at least one dimension in the nanometer size (0.1-100 nm) in three-dimensional space or are composed of them as basic units, which is approximately equivalent to the scale of 10 to 100 atoms closely arranged together. Nanogranular materials are also called ultrafine granular materials, which are composed of nanoparticles. Nanoparticles, also called ultrafine particles, generally refer to particles with a size between 1 and 100 nm. They are in the transitional area between atomic clusters and macroscopic objects. From the usual perspective of micro and macro, such a system is neither a typical microscopic system nor a typical macroscopic system. It is a typical mesoscopic system with surface effects, small size effects and macroscopic quantum tunneling effects. When people subdivide macroscopic objects into ultrafine particles (nanoscale), they will show many unique characteristics, that is, their optical, thermal, electrical, magnetic, mechanical and chemical properties will be significantly different from those of large solids. The broad scope of nanotechnology can include nanomaterial technology and nanoprocessing technology, nano measurement technology, nano application technology and other aspects. Jingrui New Materials has rich experience in the field of nanomaterials, among which nanomaterial technology focuses on the production of nano functional materials (ultrafine powder, coating, nano modified materials, etc.), performance testing technology (chemical composition, microstructure, surface morphology, physical, chemical, electrical, magnetic, thermal and optical properties). Nanoprocessing technology includes precision processing technology (energy beam processing, etc.) and scanning probe technology. [Application of Nanomaterial Aluminum Oxide in Ceramics] In traditional ceramic materials, the grains are not easy to slide, the material is brittle, and the sintering temperature is high. The grain size of nano-ceramics is small, and the grains are easy to move on other grains. Therefore, nano-ceramic materials have extremely high strength and high toughness as well as good ductility. These characteristics enable nano-ceramic materials to be cold processed at room temperature or sub-high temperature. If the nano-ceramic particles are processed and formed at sub-high temperature and then surface annealed, the nano-material can be made into a high-performance ceramic that maintains the hardness and chemical stability of conventional ceramic materials on the surface, while still having the ductility of nano-materials inside. Alumina ceramics is a ceramic material with α-Al2O3 (VK-L30) as the main crystal phase. Due to its high melting point, high hardness, chemical corrosion resistance and excellent dielectric properties, α-Al2O3 is the most stable crystal form of various forms of aluminum oxide and the only crystal form of aluminum oxide that exists in nature. The alumina ceramic structural material prepared with α-Al2O3 (VK-L30) as raw material has excellent mechanical properties, high temperature properties, dielectric properties and chemical corrosion resistance. [About the addition of alumina] Adding 0.5~1% nano-alumina (VK-L30) can reduce the sintering temperature of Al2O3 porcelain by 150~200℃, greatly saving energy. In addition, nano-alumina is not a foreign impurity, which greatly improves the product quality. [About the performance of nano-alumina sintered ceramics] (1) High mechanical strength. The flexural strength of Al2O3 porcelain sintered products can reach 250MPa, and that of hot pressed products can reach 500MPa. The purer the Al2O3 component, the higher the strength. Strength can be maintained at high temperatures up to 900°C. Its mechanical strength can be used to make device porcelain and other mechanical components. The strength of ceramics sintered with the addition of nano-alumina is increased and it is not easy to break. (2) High resistivity and good electrical insulation performance. The room temperature resistivity is 1015Ω·cm and the insulation strength is 15kV/mm. Its insulation and strength can be used to make substrates, tube sockets, spark plugs, circuit tube shells, etc. (3) High hardness. With a Mohs hardness of 9 and excellent wear resistance, it is widely used to make grinding wheels, abrasives, wire drawing dies, extrusion dies, bearings, etc. (4) High melting point and corrosion resistance. The melting point is 2050°C, which can better resist the erosion of molten metals such as Be, Sr, Ni, Al, V, Ta, Mn, Fe, and Co. It also has high resistance to corrosion by NaOH, glass, and slag. Therefore, it can be used as refractory materials, furnace tubes, glass drawing crucibles, hollow balls, thermocouple protective sleeves, etc. (5) Excellent chemical stability. Many complex sulfides, phosphides, chlorides, oxides, etc. as well as sulfuric acid, hydrochloric acid, nitric acid, and hydrofluoric acid do not react with Al2O3. Therefore, Al2O3 can be made into crucibles, human joints, artificial bones, hydroxyapatite-coated polycrystalline alumina ceramic artificial teeth, etc. (6) Optical properties. It can be made into light-transmitting materials (light-transmitting Al2O3 porcelain) to manufacture sodium vapor lamps, microwave fairings, infrared windows, laser oscillation elements, etc. (7) Ionic conductivity. It is used as solar cell material and battery material.