Ceramics have exceptional thermal properties compared to metals and plastics. Thermal expansion is low for all types of ceramics. Other properties, such as thermal conductivity, resistance to thermal shock and resistance to extreme temperatures, vary from one group of ceramics to the next.
Thermal conductivity, often denoted by λ (unit: W/m.K), is the ability of a material to conduct heat. It is defined by the amount of heat that passes through solid material when there is a difference in temperature between one side of the material and the other.
Thermal insulation is therefore the material's ability to reduce this heat transfer. This phenomenon is characterised by thermal resistance, denoted by R (unit: m².K/W).
These materials are used in a wide variety of sectors: aeronautical and spatial, energy, electronics, transport, defence, etc.
Comparative table of properties
Linear thermal expansion coefficient 25-1000°C (10-6 .K-1)
|Thermal conductivity (W/m.K)||Maximum operating temperature (°C) in air||Thermal shock resistance|
|Alumina (94%-99,8%)||7,5 to 9,5||18 to 30||1500 to 1700||+|
Zirconia MgO &Y-TZP
|10||2 to 2.5||1000 to 2000||++|
|Aluminium nitride||5,5||140 to 180||800||++|
|Sentered silicon carbide||4 to 5||80 to 125||1400 to 1900||+++|
|Sentered silicon nitride||3 to 4||20 to 25||1200 to 1500||+++|
|Quartz||0.5||1,5||950 to 1150||-|
Acceptable: + ; Good: ++ ; Very good: +++
These values are for information only and do not constitute a contractual obligation.