Investigation On Gelcasting Technique For Ceramic Powder

In this study, gelcasting utilizes its characteristics of in-situ molding to prepare the complicated shape ceramic mold which fit for the HIP. According to the situation of the core, this study also eliminates the influence of paraffin materials on the gel mold by preparing emulsion that covering the wax surface, and furthermore improves surface quality between wax mold and gel mold. This study gives a high temperature and humidity drying system based on the special characteristic that paraffin could be soften only in 80℃. This system has prevented the stress crack that formed between the dry gel mold and paraffin. Moreover, this study discusses the ceramic molding process, and investigates the facribrication of ceramic mold.Owing to the production of insulator have many problems in raw materials, production equipments, manufacturing technology, and production management, the failure rate of products is always high. The raw materials before burning could be reused but not the unqualified products after burning because they have been sintered at high temperatures and the internal mass transfer, crystal and structures have been changed. It also can't be absorbed and degraded by environment and will result in serious environmental pollution year after year. With the high speed of economic development in our country, the demands of electricity have increased constantly. Meanwhile, the unqualified product will increase as well. It is getting more and more important to find an available way to dispose the unqualified product. In accordance with the characteristic of gelcasting, this study discusses the possibility of using ceramic powder as raw material, and molding by gelcasting. By analyzing the affective factors of the ceramic slurry's viscosity, this study studies the preparation of ceramic slurry with high solid phase and low viscosity, which take the waste ceramic powder as solid phase. The viscosity of slurry is below 0.2Pas, with the solid phase reaching 59vol%. It also analyzes the response of the gelcasting and discusses the influence of the organic substance on the gel mold through adjusting the addition of organic substance and the reaction temperature to control the gel time. It can choose the ideal time from 3min to 25min according to the molding technique. Meanwhile, organic substance also has the influence on the strength of gel mold. The three-dimensional network composed by organic substance is the main source of strength. However, over many organic substances will go against to the performance of the blank during burning out and sintering. The data shows, when the monomer in proportion to crosslink is 12:1, the strength of blank is the highest for the degree of cross linking is the highest. It gives how to dry and sinter the gel mold by connecting the gelcasting mold with the characteristic of ceramic powder, and investigates gelcasting technology. By utilizing the wate ceramic powder as raw material, and molding through gelcasting, it finally producces the ceramic whose performance is close to the raw ceramic. It has a great significance for the continual development of ceramic industry.