March 10, 2019
Properties of Alumina Ceramics
- Insulation Resistant
Alumina is an excellent electrical insulator that is resistant to extremely high currents, and its resistance to electricity increases with its purity. The more pure alumina is, the higher the resistance would be.
- High Temperature Resistant
Alumina is also known to have a very high melting point and strong mechanical strength. However, its mechanical strength decreases when the temperature goes above 1000 degrees Celsius. Due to the vast difference in its coefficient of thermal expansion, its resistance to thermal shock is less effective when exposed to very high temperatures.
Hardness measures the ability of a material to endure mechanical wear and abrasion. Alumina ceramics are harder than steel and tungsten carbide tools. According to Rockwell hardness, alumina ceramics are at HRA80-90, second only to diamonds and above stainless steel.
- Abrasion Resistant
Abrasion wears down a material by rubbing it away by friction. The resistance to abrasion means a material will maintain its original structure even after mechanical wear. Alumina ceramics are high in abrasion resistance due its hardness.
- Chemical Resistance
Alumina is resistant to acids and alkalis at high temperatures because it is inert, not chemically reactive, which makes it resistant to the effects of chemicals such as solvents and salt solutions.