Process And Application Study Of Electron-heating Porous SiC Ceramic

The electron-heating porous ceramic was prepared by reactive sintering which main raw is SiC and petrol coke. It was formed through many methods, such as that the organic form is immersed in slurry, and that organic waffle-like plastics is coated with pasty mass, which the sully and the paste was made of SiC, petrol coke, PF resins and absolute ethyl alcohol.The preparation of ceramic still adopts immersion. What is different from form process is that the organic foam was preprocessed. In this experiment, the foam ceramic with different content of petro coke was studied. The application is designation of heating-water device. During the designation, porous ceramics was used as heating element instead of the foam ceramic because the porosity of foam ceramic is higher, the wall of pore is thin and the rib of pore is slender, drilling can destroy its over-all structure. To prevent the fluid from directly contacting with the ceramic during the , the insulation coatint was studied, which the coating substance is Al₂O₃ made by Sol-Gel and the method is diping and vertical sliding.By XRD,SEM,EDS etal, the microstructure and phase compositon of foam ceramics and coated porous ceramics was analyzed and discussed.The preparation of slurry in the immersion process is very important. The performance of slurry made of different content of petro coke is studied. It is concluded that the optimum performance is obtained when the consistancy of alcohol solution of PF resins is all 55.86%, which the solution is used as dispersant and plastering agents. Although the consistancy is constant,the total use level is increased with the increase the content of petro coke.After organic foam's preprocessing,the surface of pore rib becomes uneven, so the ammount of the slurry on the ribs is increased, and the antiflex strength is enhanced from 2-3Mpa to 5Mpa.Then the influence of difference in content of petrol coke on foam ceramic performance was studied. It is concluded that the resistivity is decreased with the increase of the petrol...