Alumina (Aluminium Oxide) - The Different Types of Commercially Available Grades

Key Properties

Aluminium Oxides key properties are shown below.

• High compression strength

• High hardness

• Resistant to abrasion

• Resistant to chemical attack by a wide range of chemicals even at elevated temperatures

• High thermal conductivity

• Resistant to thermal shock

Fused

White Fused Alumina is made in electric arc furnaces by passing a current between vertical carbon electrodes. The heat generated melts the alumina. The furnace consists of a water cooled steel shell and 3-20 tonne batches of material are fused at any one time. The fused alumina has a high density, low porosity, low permeability and high refractoriness. As a result of these characteristics, it is used in the manufacture of abrasives and refractories.

The only compound of silicon and carbon is Silicon Carbide (SiC), or carborundum. SiC does occur naturally as the mineral moissanite, but this is extremely rare. However, it has been mass produced in powder form for use as an abrasive since 1893. As an abrasive, it has been used for over one hundred years in grinding wheels and many other abrasive applications.

Automotive uses of SiC

One of the primary uses of Black Silicon Carbide is high performance "ceramic" brake discs. The silicon combines with the graphite in the composite to become carbon-fiber-reinforced silicon carbide (C/SiC). These brake discs are used on some sports cars, supercars, and other performance vehicles.

Another automotive use of SiC is as an oil additive. In this application, SiC reduces friction, emissions, and harmonics.

Magnesium Oxide is an inorganic salt of magnesium formed with ions of magnesium and oxygen.

It’s one of many forms of magnesium available for purchase in supplement form. It’s added to dietary supplements as well as over-the-counter medications used to treat constipation, indigestion, and headaches.

Compared with other forms of magnesium, it may be less effective at raising blood magnesium levels.