Alumina, Al2O3, is available from Ceramaret with a purity of up to 99.9%. It is a polycrystalline material with a grain size of 1 to 5 microns, an average density of 3.95 g/cm³ and a hardness of about 2000 Vickers.
Physical Properties
Property
Value
Atomic composition
>99%
Crystalline structure
Corundum
Grain size (microns)
1-5
Density (g/cm3)
3.95
Water absorption (%)
0
Mechanical Properties at 20°C
Property
Value
Vickers hardness (Hv 500g)
1800-2000
Tensile strength (N/mm2)
200-250
Bending strength (N/mm2)
200-600
Compressive strength (N/mm2)
1900-2000
Young’s modulus (N/mm2)
3.8x105
Poisson’s ratio
0.25-0.30
Fracture toughness KIC -½ (MPa.m)
4-5
Thermal Properties
Property
Value
Dilation co-efficient (20-2000°C) (°C-1)
8.4x10-6
Specific heat 100°C (J/kg.K)
930
Thermal conductivity at 20°C (W/m.K)
40
Thermal shock resistance (°C)
200
Electrical Properties
Property
Value
Resistivity at 20°C (ohm.cm)
>1014
Dielectric constant at 20°C and 1GHz
9.5
Dielectric rigidity at 50Hz (KV/mm)
30
Chemical Properties
Chemicals
Concentration
Temperature
Time
Rating
HCl
35%
Boiling
30 min
A
HNO3
70%
Boiling
30 min
A
H2SO4
98%
Boiling
30 min
A
H3PO4
90%
Boiling
30 min
B
HF
60%
20
24 hr
C
KOH solution
10%
80
7 day
A
KOH boiling
500
24 hr
C
NaOH boiling
500
24 hr
B
Na2CO3 boiling
900
24 hr
B
Na2SO4 boiling
1000
24 hr
A
KF boiling
90
4 hr
D
A: no corrosion observed
B: slightly corroded
C: middle degree of corrosion
D: heavily corroded
Note: The values quoted are typical. Ceramic property values can vary with the method of manufacture.
Source: Ceramaret SA
For more information on this source please visit Ceramaret SA
%20-%20Physical,%20Mechanical,%20Thermal,%20Electrical%20and%20Chemical%20Properties%20-%20Supplier%20Dat_files/image003.gif)
%20-%20Physical,%20Mechanical,%20Thermal,%20Electrical%20and%20Chemical%20Properties%20-%20Supplier%20Dat_files/image004.jpg)
Ceramaret SA
