Physical Properties – Alumina

PROPERTY

TEST UNIT

99.7%

ALUMINA

96 %

ALUMINA

COLOUR

WHITE

WHITE

DENSITY

Grams/cm³

3.8-3.90

3.7

POROSITY

%

NIL

NIL

FLEXURAL

STRENGTH

   20°C

MPa

           1000°C

330-400

150

355-365

150

COMPRESSIVE STRENGTH

MPa @ 20°C

2100-2500

2100

20°C

>10¹⁴

>10¹⁴

RESITIVITY

500°C

3.0 x 10¹²

4 x 10⁹

1000°C

1.0 x 10⁶

1.0 x 10⁶

DIELECTRIC STRENGTH

1/4/6.35mm

KV/mm¹

9.3

8.2

THERMAL CONDUCTIVITY

W/m/K

29-36

25

HARDNESS

R45N

82-84

80-81

COEFFICIENT of LINEAR EXPN.

X10^-6

@20-1000°C

8.1

@20-1000°C

8.1