Item

Test Condition

Unit Symbol

95%Alumina ceramics

99%Alumina ceramics

99.7%Alumina ceramics

The main chemical ingredient

Al2O3

Al2O3

Al2O3

Bulk Density

g/cm3

3.6

3.89

3.96

Maximum Use Temperature

1450°C

1600°C

1650°C

Water absorption

%

0

0

0

ROHS Hardness

≥85

≥89

≥89

Flexural strength

20° C

MPa (psi x 10³)

358 (52)

550

550

Compressive Strength

20° C

MPa (psi x 10³)

2068 (300)

2600(377)

2600(377)

Fracture Toughness

K(I c)

Mpa m^1/2

4-5

5.6

6

Coefficient of

thermal expansion

25-1000° C

1X 10^-6/°C

7.6

7.9

8.2

Coefficient of

thermal conductivity

20° C

W/m °K

16

30.0

30.4

Thermal Shock Resistance

Tc

°C

250

200

200

Dielectricity constant

1MHz.25°C

9

9.7

9.7

Dielectric strength

ac-kV/mm (ac V/mil)

8.3 (210)

8.7 (220)

8.7 (220)

Volume Resistivity

100°C

ohm-cm

> 10¹³

> 10¹⁴

> 10¹⁴