| Material
A:Steatita (SiO2) |
Material
B: (B) Alumina (Al2O3) |
| Denomination |
Units |
Si
O2 |
Denomination |
Units |
Al2
O3 >95% |
Al2
O3 > 98 % |
Al2
O3 >99 % |
| Porosity |
% |
0 |
Porosity |
% |
0 |
0 |
0 |
| Density |
gm/cm³ |
2.60 |
Density |
gm/cm³ |
3.50 |
3.70 |
3.85 |
| Hardness
Rockwell |
R45N |
68 |
Hardness
Rockwell |
GPa |
13.0 |
15.0 |
16.0 |
| Flexural
Strength |
Mpa |
125 |
Flexural
Strength |
Mpa |
300 |
325 |
400 |
| Compressive
Strength |
Mpa |
900 |
Compressive
Strength |
Mpa |
2000 |
2250 |
2400 |
| Young's
Modulus |
Gpa |
100 |
Young's
Modulus |
Gpa |
330 |
335 |
385 |
| Co.
off. of Thermal Expansion |
mm
/ °C25° -700°C |
8.0
x 10-6 |
Co.
off. of Thermal Expansion |
mm
/ °C25° -700°C |
7.0
x 10-6 |
7.5
×10-6 |
8.0
×10-6 |
| Thermal
Shock Resistance |
°C |
190 |
Thermal
Shock Resistance |
°C |
165 |
175 |
185 |
| Thermal
Conductivity (25 ºC) |
W/m.K |
3.0 |
Thermal
Conductivity (25 ºC) |
W/m.K |
23.0 |
26.0 |
28.0 |
| Maximum
Withstanding Temp. |
°C |
1000 |
Maximum
Withstanding Temp. |
°C |
1300 |
1600 |
1650 |
| Dielectric
constant 25°C |
1
MHz |
6.1 |
Dielectric
constant 25°C |
1
MHz |
9.6 |
9.7 |
9.8 |
| Dielectric
Strength |
KV/mm |
25.0 |
Dielectric
Strength |
KV/mm |
25.6 |
27.2 |
28.5 |