Alumina ceramics

High precission alumina ceramics for complex technical elements

Characteristics

Crytur produces complex 3D shapes from engineering grade alumina with high ratio of polycrystalline Al2O3 and low porosity. Production process involves precision machining and several highly controlled sintering steps.

Resulting material has unique combination of physical properties

Durability (high mechanical strength, high hardness, high stiffness, good wear resistance)
Resistance (high temperature resistance, high corrosion resistance)
Electrical (high dielectric strength, low dielectric loss)
Thermal (high melting point, high thermal shock resistance, good thermal conductivity)
Thermo-mechanical (low thermal expansion)

Material characteristics

Physical properties
Composition	98% Al₂O₃
Porosity	Fully gas tight
Density	3850 kg/m³
Color	White
Thermal properties
Thermal conductivity	29 W/(m * K)
Coeficient of thermal expansion (300 - 900K)	8x10^_-6 /K
Specific heat kapacity	880 J/(kg * K)
Maximum service temperature	1650 °C
Fracture toughness tests
Fracture toughness	4.3 MPa*m^1/2
Flexural strenght	386 MPa
Modulus of elasticity	331 GPa
Compressive strength	2070 MPa
Vickers pyramids number	1340 HV
Electrical properties
Dielectrict strength	9.3 kV / mm
Dielectrict constant (1MHz)	9.4
Specific resistance (20 °C)	10¹⁶ Ω * m^-1

Application

Alumina ceramics is widely used in various applications with challenging mechanical, thermal or chemical conditions. Low porosity makes it suitable in high vacuum applications. It is also frequently used for electric insulation and electronic packaging.