Quality And Grade Of Calcined Silicon Carbide

After strict implementation of the proposed SiC sintering process, due to the different heating intensity and heating time in different parts of the furnace, the obtained SiC product grows in a radioactive direction around the core of the graphite carbon rod, so people follow the same shape to take out the products individually. The calcined silicon carbide, the closer it is to the core, the purer it is, generally divided into five grades.

1) Dense bulk crystals ------ known as first-grade emery (SiC), it is close to the graphite carbon mandrel and is green and sometimes black, which is due to the colloidal carbon entering the emery (SiC) crystallization caused by the composition.

2) Emery (SiC) composed of dispersed small crystals. Is a secondary emery.

3) This area does not reach the crystallization conditions, and only produces brittle cryptocrystalline silicon carbide (SiC), also known as amorphous silicon carbide. It surrounds a layer of small crystalline silicon carbide (SiC).

4) Gray-green material body, it belongs to material body, not called emery. Deposited on amorphous silicon carbide (SiC) surfaces. Used for underfeeding.

5) Unreacted materials.