Silicon nitride rods are a commonly used ceramic material in the metallurgical industry due to their uniform performance at high temperatures. Silicon nitride electrodes have excellent thermal shock resistance due to their microstructure. Si3N4 also has excellent creep and oxidation resistance, and its low thermal conductivity and high wear resistance also make it an excellent material capable of withstanding the conditions of most industrial applications.

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

*Tested at room temperature

*The above information is for comparison only. The exact characteristics will vary depending on the manufacturing method.

Typical properties of silicon nitride ceramics

-High strength over a wide temperature range

-High fracture toughness

-High hardness

-Excellent wear resistance

-Low thermal expansion and high thermal conductivity

-Good thermal shock resistance

-Good chemical and oxidation resistance

Silicon Nitride Rod Applications

-Silicon Nitride Welding Rod The welding rod is an integral part of a typical high-frequency resistance welding (HF-ERW) system. It serves the dual function of applying pressure and delivering the workpiece through the welding machine.

-High-precision, high-density silicon nitride ceramic plunger rods, ceramic motor shafts, ceramic rollers, and other bearing accessories.

Silicon Nitride Ceramic Plunger Rods

Silicon nitride ceramic plunger rods do not require preforms, and powders do not require the addition of molding agents. The most critical part is the hot pressing mold (sintered at 1,700-1,800°C). Graphite molds are of low strength and to guarantee the pressure during hot pressing, the thickness of the negative mold must be very thick as the size of the hot-pressed sample increases! Large, high-strength graphite molds are expensive and there is no guarantee that they will not break during use! Sintered ceramics can be sliced or precision ground with diamond wheels to a surface roughness of 0.025 microns (mirror luster), and 0.006 microns (mirror luster).

Packing

Silicon nitride Rods use appropriate outer boxes and internal buffer materials, and some components are also vacuum-packed.