Alumina

AluminaAlumina (Al2O3) is one of the most widely used, general purpose technical ceramics. Alumina provides several benefits including being extremely hard and wear resistant across a wide temperature range. Alumina is produced by heating tightly packed alumina powder with a binder material. This process produces commercial grades of 90 - 99.95%, with higher purity providing higher hardness.

90%-97% Alumina: most suitable for metal deposition due to its large grain structure.

98%-99.95% Alumina: Commonly available for extruded shapes at low cost.

Zirconia Toughened Alumina (ZTA): is a material that is tougher than Alumina with improved hardness, strength and thermal properties especially at high temperatures.

Alumina applications:

  • Pump piston sleeves
  • Bushings & insulators
  • Impellers
  • Valve seals & seats
  • Medical implants
  • Die & cutting tool inserts
  • Bearing components

We can machine Alumina into a variety of sheets, cylinders, discs and other complex shapes.

Property Value

General
Chemical Formula Al2O3

Mechanical
Density 3.88 g/cm3
Hardness 2000 Knoop
Modulus of Elasticity 48 - 54 x 106 psi
Flexural Strength 57 kpsi
Compressive Strength 368 kpsi
Poisson's Ratio 0.23 - 0.26
Fracture Toughness 4.3 MPa m1/2

Electrical
Dielectric Strength 210 - 220 ac V/mil
Dielectric Constant 9.7 (@ 1MHz)
Volume Resistivity >1014 Ohm-cm

Thermal
Coefficient of Thermal Expansion 5.1 - 7.2 x 10-6/°C
Thermal Conductivity 30.3 - 35.0 W/mK
Specific Heat 0.20 cal/g °C
Shock Resistance 200°C Diff
Maximum Working Temperature 1750 °C