Aluminum oxide is an excellent electrical insulator. Its electrical resistance is directly proportional to its purity and increases with temperature. It also has a high melting point and a very high mechanical strength. However, its mechanical strength diminishes when exposed to temperatures over 1000°C. Other properties of alumina include its high thermal expansion coefficient, high chemical stability, and high corrosion resistance.
A-alumina is the only stable alumina phase at all temperatures
A-alumina is the only stable crystalline phase of alumina at all temperatures. This property is due to transition alumina phase transformations, which are characterized by structural changes but no shrinkage. The transformation of 6-Al2O3 to a-alumina begins at 1050degC and reaches its maximum at 1192degC.
The electronic band gap of AlO2 and Al4O7 is less than one eV. This is due to peroxo-groups, which decrease the electronic band gap of Al4O7 and AlO2.
It is inert
Aluminum oxide is an inert material that is used in many different chemical, industrial, and commercial applications. It is insoluble in water and is a white, odorless powder. It is also a catalyst and desiccant. Its chemical properties vary depending on the preparation process.
It is used as a filler for plastics
Aluminum oxide is a common filler for plastics, but it also has other uses. It reduces the cost of the plastic and increases its strength when mixed with the polymer. The particle’s size and shape affects the enhancement. For example, a needle-like particle will be less abrasive than a flaky or broad one.
Aluminum oxide, or alumina, is a white chemical compound. It’s also inert, making it an ideal filler for plastics. It’s also a common ingredient in cosmetics and sunscreens. Alumina is also found in many glass formulations, including aluminosilicate glass. Moreover, it’s used to catalyze a variety of useful industrial reactions, including the dehydration of alcohols to alkenes.
It is used as an abrasive in blast preparation and finishing
Aluminum oxide is a brown to white virgin-fused abrasive that has outstanding strength and hardness. Its unique chemical structure makes it ideal for a variety of blasting applications, and it is available in many different grades. Aluminum oxide is also very durable and can be recycled multiple times. Its low silica content makes it an environmentally friendly option for many applications.
Aluminum oxide is available in a variety of forms and is one of the most widely used abrasives. It is relatively safe to use because it contains less than 1.5% free silica, which makes it a safer option than sand. Aluminum oxide also has a consistent grit size that increases with increasing grit size. This makes aluminum oxide a great choice for abrasive applications, especially those that require a high level of precision.
It is used as a catalyst
Aluminum oxide is a chemical compound that promotes chemical reactions. This compound has a low bulk specific gravity and a particle size of 20 grit or finer, which makes it fluid and can be used to speed up reactions. It can also be suspended in any gas. For the particles to be suspended, the gas must be forced through the mass of particles at a sufficiently high velocity. This requirement is decreased as the particle size decreases.
Summary:
Aluminum oxide is used in a wide range of chemical reactions. Its high melting and boiling points make it an excellent thermal insulator, making it valuable in high-temperature furnaces. It is also used as a ceramic material and a plastic filler. It is also an important ingredient in the manufacture of rubies, sapphires, and other precious gemstones.