Silicon Nitride Ceramics Manufacturer

What are the material properties of silicon nitride ceramic materials?

Mechanical properties

High strength: The bending strength of silicon nitride ceramics can reach more than 350MPa, which is more than 10 times that of ordinary steel.
High hardness: The Vickers hardness of silicon nitride ceramics can reach more than 1700HV, which is more than 2 times that of ordinary ceramics.
High toughness: The fracture toughness of silicon nitride ceramics can reach more than 10MPa·m^0.5, which is more than 100 times that of ordinary glass.
Good wear resistance: The wear resistance of silicon nitride ceramics is more than 5 times that of steel and more than 2 times that of cemented carbide.

Thermal properties

Low thermal expansion coefficient: The thermal expansion coefficient of silicon nitride ceramics is only (1~3)×10^-6/℃, which is less than 1/10 of steel.
High thermal conductivity: The thermal conductivity of silicon nitride ceramics is 60~120W/(m·K), which is more than 5 times that of ordinary ceramics.
Good thermal shock resistance: The thermal shock resistance of silicon nitride ceramics is more than 50 times that of steel and more than 100 times that of glass.

Chemical properties

Good chemical corrosion resistance: Silicon nitride ceramics can withstand corrosion from strong acids, strong alkalis and organic solvents.

Good oxidation resistance: Silicon nitride ceramics can remain stable in dry oxidizing atmospheres below 1200°C.

Electrical properties

Excellent electrical insulation: The volume resistivity of silicon nitride ceramics is more than 10^11Ω·cm.

How do silicon nitride ceramic materials form shapes such as tubes and rotors?

1. Pressing method

The pressing method is a method of uniformly mixing silicon nitride powder with additives and then pressing and molding. After pressing and molding, the green body can be dried and sintered to obtain dense silicon nitride ceramic products. The pressing method is suitable for manufacturing silicon nitride ceramic products with simple shapes and small sizes.

2. Slurry injection method

The slurry injection method is a method of making slurry from raw materials such as silicon nitride powder, binder and water, and then injecting the slurry into a mold for molding. After the green body is dried and sintered after slurry injection molding, a dense silicon nitride ceramic product can be obtained. The slurry injection method is suitable for manufacturing silicon nitride ceramic products with complex shapes and large sizes.

3. Turning method

The turning method is a method of processing silicon nitride ceramic rods into the required shape and size using a lathe. The turning method is suitable for manufacturing high-precision, smooth-surfaced silicon nitride ceramic products.

4. Hot Isostatic Pressing

Hot isostatic pressing is a method of sintering silicon nitride powder into a mold under high temperature and high pressure. Hot isostatic pressing can produce silicon nitride ceramic products with high density and low porosity.

5. 3D Printing

3D printing is a rapid prototyping technology that has also been applied to the manufacture of silicon nitride ceramic products in recent years. 3D printing can produce silicon nitride ceramic products with complex shapes and fine structures.

The specific method to be selected depends on factors such as the shape, size, precision and performance requirements of the silicon nitride ceramic product.

Here are some specific examples:

Silicon nitride ceramic tubes are usually prepared by pressing or grouting. For tubes that require precision, turning can be used for finishing.
Silicon nitride ceramic rotors are usually prepared by pressing or grouting. For rotors that require high precision, 3D printing technology can be used for manufacturing.