Technical indicators
|
 |
| Technical data |
|
Item
|
unit
|
Test standard
|
Alumina
|
|
99%
|
94-96%
|
85%
|
50%
|
|
Density
|
g/cm3
|
GB2413
|
≥3.8
|
≥3.72
|
≥3.42
|
≥2.64
|
|
Particle average size
|
um
|
Section microscopy
|
6
|
6
|
6
|
12
|
|
Water absorption
|
%
|
GB2413
|
0
|
0
|
0
|
0
|
|
Bubble
|
-
|
GB775.1
|
0
|
0
|
0
|
0
|
|
Colour
|
-
|
-
|
white
|
white
|
white
|
white or brown
|
|
Flexure strength
|
MPa
|
GB/T5593
|
≥338
|
≥320
|
≥290
|
≥160
|
|
Elasticity modulus
|
GPa
|
GB5594.2
|
≥350
|
≥300
|
≥220
|
≥140
|
|
Poisson's ratio
|
-
|
GB5594.2
|
0.20～0.25
|
0.20～0.25
|
0.20～0.25
|
-
|
|
Compressive strength
|
MPa
|
GB/T5593
|
≥2400
|
≥2000
|
≥1500
|
≥500
|
|
Hardness
|
GPa
|
HRA
|
82
|
80
|
73
|
70
|
|
Tension strength
|
MPa
|
GB775.3
|
≥240
|
≥190
|
≥150
|
≥45
|
|
Impact toughness
|
MPa·m1/2
|
GB/T14389
|
4～5
|
4～5
|
3～4
|
-
|
|
Thermal conductivity coefficient
|
W/m·°K
|
GB5598
|
≥27
|
≥24
|
-
|
-
|
|
Coefficient of linear expansion
|
1×10-6/℃
|
GB5594.3
|
6.5～8.2
|
6.5～8.0
|
6.5～8.5
|
5.0～6.0
|
|
Specific heat
|
KJ/kj·°K
|
GB5598
|
0.8～0.9
|
0.8～0.9
|
-
|
-
|
|
Thermal shock resistance
|
℃
|
GB/T5593
|
800
|
800
|
420
|
190
|
|
Max. Tem.
|
℃
|
-
|
1600
|
1600
|
1400
|
-
|
|
Dielectric strength
|
ac/kV/mm
|
GB775.2
|
≥18
|
≥18
|
≥15
|
≥20
|
|
Dielectric constant
|
-
|
GB5597
|
9～10
|
9～10
|
≤10
|
≤7.5
|
|
Dielectric loss
|
×10-4
|
GB5594.4
|
≤2.5
|
≤2.5
|
≤8
|
≤20
|
|
Specific resistance
|
25℃
|
Ω·cm
|
GB5594.5
|
≥1014
|
≥1014
|
≥1014
|
≥1014
|
|
500℃
|
Ω·cm
|
GB5594.5
|
≥1010
|
≥109
|
≥108
|
-
|
|
1000℃
|
Ω·cm
|
GB5594.5
|
≥106
|
≥106
|
-
|
-
|
|
|
