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 -
| Material | Thermal 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