Development of Silicon Carbide Ceramic Foam Filter

Silicon carbide ceramic foam filter Development Abstract: silicon carbide, kaolin, alumina powder as raw material. Mixed rare earth oxide as a sintering aid. Rheological made good water-based ceramic slurry. Immersed in the foam. A uniform coating on the foam. Final firing into having high porosity, bulk density, good strength, thermal shock resistance and strong silicon carbide ceramic foam filter. Study on the water, ethanol, NaOH, CMC and NaOH + CMC polyurethane foam surface finish. The study found: foam after mixing NaOH and CMC process can get the best effect linked to pulp. Tu linked to the amount of slurry in a certain range with increasing solids loading and better. When the solid content of 75%. Obtain uniform and stable slurry suitable for dipping. Secondary enrobed coating can significantly increase the amount of foam. The pore diameter is a bar linked to pulp twice. Increasing the strength of ceramic foam filters.

Silicon carbide ceramic foam having a large specific surface area, low density, high temperature, high permeability. And excellent insulation properties. Widely used in molten metal filtration, thermal sensor, catalyst supports and automobile exhaust and other fields. Since SiC is difficult to directly sintering. Using atmospheric sintering approaches to the production of high density of SiC ceramics. The special methods must be used against the second phase materials to help promote their densification. In order to promote sintering. Binding agents need to be added.

Has come up with the binding agents are mainly three kinds: Si3N4 combination, β-SiC Al2O3-SiO2 binding and binding. Since the first two methods require and fired in a reducing atmosphere in a special furnace. Demanding conditions. The Al2O3-SiO2-oxidizing atmosphere can be combined in a conventional sintering furnace. And a low sintering temperature, it is widely used in the actual production. Join Al2O3 can promote SiC sintering. The main complex is the formation of a liquid phase component Al2O3-SiO2 impurities. SiC is dissolved by this liquid phase precipitation process to transfer substances. Densification. Adding a small amount of rare earth oxides. Can promote sintering SiC-Al2O3 ceramic. Increasing its density. In order to achieve the increase in intensity.

China's rare earth resources are very rich. And low prices. Rare earth oxides for most cast iron, aluminum, copper alloy and zinc alloy castings does not produce side effects. It is an ideal sintering aid. Currently very few reports in this regard.