1. SSiC mechaical seal ring manufacturing process is mainly: raw material treatment - molding - sintering - grinding and grinding - assembly. The detailed manufacturing process is as follows:
Raw material treatment process: The specific surface determination of SiC raw materials with different milling time and feed ball ratio.
2. Forming process: Using dry pressing and isostatic pressing process, the former is suitable for simple shape, large batch products, the latter is more suitable for a small number of single, complex shape products, and the density and performance of isostatic pressure silicon carbide sealing ring are better than dry pressing products.
3. Hot pressing process: The process of combining the pressure and sintering process is called hot pressing. Press-free sintering process: The molded silicon carbide billet is sintered in the furnace at high temperature under the protective gas called press-free sintering.
4. Grinding and grinding: Silicon carbide is a hard and brittle ceramic material, in order to prevent the product from falling off the edge, it must be blunted at an acute Angle. Only by selecting the appropriate abrasive and particle size, strictly controlling the grinding rate and the necessary tooling conditions, can the surface roughness requirements of the seal end face be achieved.
5. Assembly process: In addition to the overall structure of the silicon carbide seal ring, a large number of hot sleeve insert structure is used, and the ring base material mounted with the silicon carbide seal ring is mostly Chin alloy.
Because silicon carbide is a highly covalent non-oxide material, the ionic property of the Si-C bond is only 14%. The high stability of the Si-C bond on the one hand gives SiC a high melting point and hardness and chemical inertness, on the other hand, the diffusion rate during sintering is quite low. Only with the participation of additives, the purity and fineness of the raw material can be controlled, and it can be sintered by pressurizing or under a specific atmosphere.
