Low pressure casting holding furnaces use silicon nitride riser tubes.
Riser tubes, which are essential components for low pressure casting holding furnaces, have gone through multiple "generations" of material development. Prior to the development of the silicon nitride riser, several fundamental issues with the usage of the riser were essentially resolved for materials ranging from metal to ceramic, from ordinary ceramic to composite ceramic:
1. Corrosion resistance: In high-temperature metal solutions, the riser tube composed of metal is quickly corroded. Even when a riser made of composite ceramics, like silicon carbide, is utilised, severe corrosion still occurs. Service life is between one and two months.
2. Slag buildup: The conventional liquid riser tube is quite porous. Corrosion makes it simple to manufacture slag accumulation, which causes the pipeline to narrow or possibly get blocked.
3. Make sure the product is pure. Because the traditional metal riser will corrode and introduce impurities into the final product, silicon carbide risers will only be used to produce low-end products. The amount of impurities has a significant impact on both product quality and industrial advancement. The metal solution is not contaminated by silicon nitride.