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Material Alumina Al2O3Zirconia ZrO2Mixed oxides ZrO2/Al2O3Silicon carbide SICSilicon nitride Si3N4Boron nitrideMetal
Brief description Al2O3 purity 96%Al2O3
Mg-PSZ MgO partially stabilizedY-TZP Y2O3 partially stabilizedZrO2 particle-reinforcedAl2O3
SiSiC Si-infiltrated with 8-12% free SiliconSSiC sintered without free siliconHP SIC hot-pressed without free siliconHP SN hot-pressedSSN sinteredHP BN*
C-15* plain steel
Color whitewhiteyellowwhitewhitewhiteblackblackblackblackgreywhite-
Structural properties              
Open porosity%0000000000000
Average crystal sizeµm105500.70.70.51511055--
Mechanical properties              
Vickers hardness (HV10)MPa14001800120013001400170022002500250016001450190700
Compressive strengthMPa280028001600220021002600120022002900250025001601000
Flexural strengthMPa290340500100082060032042043085075070/30**450
Fracture toughnessMPam½-
Elastic modulus*GPa35038020020022036035041044032030030/25**210
Weibull modulus*-1010122020201210121815--
Poisson's ratio*-
Thermal properties              
max. Application temperature*
under protective gas
max. Application temperature*
in air
Specific heat at 20°CJ/Kg K9009005505006007009506501000750700-462
Thermal conductivity at 100°CW/mK25302262585759035353550
Coefficient of thermal expansion(20°C - 1000°C)10-6K-18.58.510.510.5994.
Thermal shock resistance*K180190260300300250400350450400450--
Electrical properties              
Volume resistivity at 20°CΩcm1014101410101091091090.210-1001021010101210140.0015
Volume resistivity at 400°CΩcm10111012104104104107-------
Volume resistivity at 1000°CΩcm1041071031031021050.050.20.2107107109-
Dielectric strengthkV/mm>18>25---------39-
Dielectric constant at 20°C and 1 GHz-89>20>20>20----2020--
Dielectric loss factor (tgΔ)
at 20°C and 1 GHz
Dielectric loss factor (tgΔ)
at 20°C and 10 kHz

Alumina (Al2O3)

Values are benchmarks for easy comparison. Other materials on request

The economic all-around solution

Alumina is the leading material among Technical Ceramics and is the most commonly and widely used due to its superior versatile qualities such as material properties, ease of manufacture, wide availability and economic prices.


Specific properties

Very high use temperature
Very good electric insulation
Very high compressive strength
Medium mechanical strength
Medium thermal conductivity
Low density
Biocompatibility (food safe)
High corrosion resistance


Sealing and sliding elements in valves
Wear resistance in mechanical and plant engineering
Wire guides used in the cable and wire industry
Nozzles used in the pressure washing industry
Thermal protection tubes
High-temperature systems