Alumina Oxide Material Properties

Alumina Oxide (Al2O3), also known as Alumina, is a widely used engineering ceramic due to its high performance at a cost effective price. Generally white or creamy beige, it is available in various levels of purity. Properties include high levels of mechanical strength, compressive strength, hardness, corrosion & wear resistance. Performance characteristics include low dielectric constant and low thermal expansion. It is chemically inert and biocompatible. Alumina is a good selection for high temperature or corrosive environments and high wear applications.

Applications for precision balls include: bearings, check valves, pumps, gauges, flow meters, medical devices, metrology instrumentation

Alumina Oxide

chemical composition >99.9% Al2O3
crystalline structure corundum
density 3.90 g/cm3
porosity 0
hardness at 20°C 15.7 GPa
Young’s modulus 365 GPa
Poisson’s ratio 0.25
tensile strength 200 – 250 N/mm2
bending strength 200 – 600 N/mm2
compressive strength 1900 – 2000 N/mm2
fracture toughness 4 – 5 MPa.m
thermal conductivity 40 W/m.K at 20°C
thermal shock resistance 200°C
melting point 2050°C
specific heat 930 J/kg.K (at 100°)
electrical resistivity 1012 Ω.cm at 20°C
108 Ω.cm at 500°C
dielectric strength 1 x 104 KV/m
dielectric constant 10.0, 1MHz
*values are for guidance only