|
|
| Thermal properties |
|
|
|
| Coefficient of
Expansion |
5.3
(10°/K) // c axis @ 300 K
4.5 (10°/K) ┴ c axis @ 300 K
|
| Max Usage
Temperature |
2000
°C
|
| Thermal conductivity |
40 (W/m.K) @ 300 K
4 (W/m.K) @ 1500 K |
| Specific heat |
750 (J/kg.K) |
|
|
| Mechanical
properties |
|
|
|
| Young
Modulus |
4.4 x 105 MPa
@ 300 K |
| Shear Modulus |
400MPa @ 300 K |
| Knoop
Hardness |
1.9 x 105 MPa |
| Traction resistance |
190 MPa @ 300 K |
| Poisson constant |
0.30 |
|
|
| Electrical
properties |
|
|
|
| Di-electric
constant |
10.6 // c axis @ 300K; 106Hz
8.6 c axis @ 300K; 10 6Hz |
| Loss Coefficient |
<
103 @ 300K |
| Di-electric
Resistance |
48 x 106V/m
@ 60Hz |
| Resisitivity |
1016ohm-cm
@300K
1011ohm-cm @ 573K |
|
|
| Optical properties |
|
|
|
| Transmission |
in the visible: excellent
0.75...4.5μm:
≥ 85%
0.25...0.4μm: 60% |
| Refractive Index @
0.5893μm |
1.760 // c axis
1.768 ┴ c axis |
| Puissance
dispersivity (nf-nc) |
0.011; λf
= 0.4861μm
λ c
= 0.6563μm |
| Emissivity |
<
0.02 @ 1153K
λ = 2.6 @ 3.7μm |
| dn/dT |
13 x 10-6K-1 |
|
|
|
Transmission
Curve
|
|
|
