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.
Resistance to extreme temperatures is the ability of a ceramic to retain its physical and chemical properties at temperatures above 1,000°C. The sintering temperature (firing temperature of a ceramic) provides it with its resistance to high temperatures as, generally, the structure of this ceramic will not change below this processing temperature.
A ceramic that withstands temperature variations, high temperatures and thermal shock is categorised in the group of refractory ceramics.
These materials are used in a wide variety of sectors: aeronautical and spatial, energy, transport, engineering (equipment manufacturers, special machines, processing equipment), defence, etc.
Comparative table of properties
Comparative table of thermal 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.