Drawing No. EH–MT–004 // Engineering Materials
Alumina Ceramic Properties
Reviewed August 2026
Alumina is the most widely used engineering ceramic. The AO480S reference combines high stiffness, hardness, electrical insulation and moderate thermal conductivity.
Representative properties
The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.
What changes these properties?
Engineering variability
- Strength follows flaw statistics and depends on specimen size, surface finish and machining damage.
- Porosity and purity strongly affect thermal conductivity and dielectric properties.
- CTE and thermal conductivity vary with temperature.
- Design of brittle ceramic components should use Weibull/statistical strength methods when failure probability matters.
Selection note
Common for wear parts, electrical insulators, substrates, valve components and precision mechanical parts needing hardness and chemical stability.
Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.
How to interpret this material
Stiffness
Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.
Strength / failure
Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.
Thermal response
Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.
Technical sources
The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.