Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

Is it true that ceramics are not always hard, brittle and insulating?

   

Frequently Asked Questions

The common properties exhibited by ceramic materials (a function of very strong ionic and covalent bonding) include: high strength (particularly in compression); thermal and electrical insulation; and low toughness.

However, the wider range of properties available from ceramic materials is not widely appreciated. For example:

  • Whilst ceramics are perceived as electrical and thermal insulators, ceramic oxides (initially based on Y-Ba-Cu-O) are the basis for high temperature superconductivity, i.e. the most electrically conducting materials known to man
  • Diamond, beryllia and silicon carbide have high thermal conductivities - comparable to aluminium and copper -

    MaterialThermal conductivity
    (W/m.k)
    Diamond 2000
    Beryllia 215
    Silicon carbide 270
    Aluminium 220
    Copper 315
  • Appropriate processing can overcome inherent stiffness to allow the production of ceramic springs
  • Monolithic ceramics such as zirconia and ceramic composites have been produced, with a fracture toughness about half that of steel - 20 compared with 50 MPa.m 0.5

For more information please email:


contactus@twi.co.uk