Americen loved high purity alumina ceramic tube used in furnace

Items

performance index

Measuring Unit

High purity Alumina

99 Alumina

85 Alumina

1

Al₂O₃

%

99.7

99.3

85

2

SiO₂

%

less than0.1

—

—

3

Density

g/cm³

3.95

3.88

3.2

4

Wter absorption

%

0

0.01

0.2

5

Cld compressive strength

MPa

450

350

200

6

20 degree Celsius leak rates

Torr/L.sec

less than10^-11

less than10^-11

less than10^-11

7

Twisting in high temperature

mm

1700 degree Celsius 0.2 allowance

1600 degree Celsius 0.2 allowance

1400 degree Celsius 0.2 allowance

8

Bonding in high temperature

1700 degree Celsius non-caked

1600 degree Celsius non-caked

1400 degree Celsius non-caked

9

20—1000 degree Celsius coefficient of

thermal expansion

mm.10^-6/degree Celsius.m

8.6

8.2

8.2

10

Thermal conductivity

W/m.k

25

25

25

11

Electric insulation strength

KV/mm

20

20

15

12

20 degree Celsius direct current

insulating resistance

Ohm/cm

10¹⁴

10¹⁴

10¹⁴

13

High-temperature

insulation resistance

1000 degree Celsius MΩ

≥0.08

≥0.08

≥0.08

1300 degree Celsius MΩ

≥0.02

≥0.02

≥0.02

14

Thermal shock resistance

1550 degree Celsius 6 times not cracked

1550 degree Celsius 6 times not cracked

1300 degree Celsius 3 times not cracked

15

Maximum service temperature

degree Celsius

1900