Item

Test Condition

Unit&Symbol

95%Alumina ceramics

99%Alumina ceramics

The main chemical ingredient

Al2O3

Al2O3

Bulk Density

g/cm3

3.7

3.8

Maximum Use Temperature

1600°C

1700°C

Water absorption

%

0

0

Flexural strength

20° C

MPa (psi x 103)

358 (52)

550

Compressive Strength

20° C

MPa (psi x 103)

2068 (300)

2600(377)

Fracture Toughness

K(I c)

Mpa m1/2

4-5

5.6

Coefficient of

thermal expansion

25-1000° C

1X 10-6/°C

7.6

7.9

Coefficient of

thermal conductivity

20° C

W/m °K

16

30.0

Thermal Shock Resistance

Tc

°C

250

200

Dielectricity constant

1MHz.25°C

9

9.7

Dielectric strength

ac-kV/mm (ac V/mil)

8.3 (210)

8.7 (220)

Volume Resistivity

100°C

ohm-cm

> 1013

> 1014