Silicon Nitride Thermocouple Protection Tube / Sheath has the best thermal conductivity when used in aluminum smelting, and can quickly respond to the temperature sensor in the smelting of non-ferrous metals such as aluminum. Excellent shock resistance and light weight make it easier to operate and maintain and will last for many years.

In the light metal casting industry, to control the molten metal solution at the optimal pouring temperature, immersion heating is used, in which the heat source/thermocouple is inserted into the middle of the metal solution. Silicon nitride ceramic protection tubes are resistant to heat, and thermal shock, and have excellent corrosion resistance, maintaining the purity of the molten metal and providing a long service life.

Silicon nitride Performance

Item

Unit

Si3N4

Type

–

Gas pressure sintered

Density

g/cm3

3.2-3.3

Color

–

Black, Grey

Young Modulus

GPa

300~320

Vickers Hardness

GPa

15 – 17

Compressive Strength

MPa

2200

Bending Strength

MPa

600-1000

Thermal Conductivity

W/m.K

20-30

Thermal Expansion

10-6/°C

3.2

Max. Working Temp.

°C

1200

Volume Resistivity

Ω ·cm

> 1014

Dielectric Constant

–

6

Dielectric Strength

kV/mm

12

Fracture toughness

MPa·m1/2

5.0-7.0

Specifications of Silicon Nitride Thermocouple Protection Tube

OD

ID

L

Shape

Tube joint

16-30mm

4-24mm

200mm-1200mm

1. Conventional shape is cylindrical

2. Sheath with outer diameter >30mm can be customized upon request

Tube joint can be flanged, threaded, or ring grooved according to customer requirements

Properties of Silicon Nitride Thermocouple Protection Tube

Silicon Nitride Thermocouple Protection Tube is used to protect thermocouples measuring the temperature of the aluminum liquid and titanium liquid. It uses air-pressure sintered silicon nitride material. Characteristics:

  1. Does not corrode with molten aluminum, and does not adhere to molten aluminum on the surface, which is more conducive to improving the quality of aluminum products;
  2. It has strong oxidation resistance and can be used for a long time in the air below 1000 degrees Celsius without oxidation;
  3. 100% dense, liquid aluminum cannot be immersed in it, the silicon nitride produced by the reaction sintering process has a very short service life, the material has many pores, and liquid aluminum will penetrate in the long term;
  4. Strong thermal shock resistance;

Application of the Silicon Nitride Thermocouple Protection Tube

-Protect thermocouples measuring the temperature of aluminum liquid and titanium liquid

Packing

Silicon Nitride Thermocouple Protection Tubes use appropriate outer boxes and internal buffer materials, and some components are also vacuum-packed.