Research And Development Of High Performance Alumina Ceramics

The function and its application of alumina ceramic in various industries, the characteristics of the process, process conditions and influencing factors, as well as preparation of low viscosity and alumina ceramic slurry of high solid content were discussed in the paper. The main advantages and disadvantages of alumina ceramic molding were analyzed and the forming requirements of complex components were given, and gelcasting process was elaborated. The characteristic of the process, the advantages of processes and the key factors of molding processes were discussed, and the improvements of gelcasting process were investigated.In order to overcome the large amount of organic matter in the process of gel injection molding, the pollution of the process and the higher curing temperature, and the higher temperature, a self-synthesized carboxymethyl cellulose-methyl methacrylate graft copolymer was used to replace the original acrylamide system in this paper. The effect of different parameters on the properties of the slurry and ceramic green body was studied. The properties of ceramic green body were characterized.The effects of the dispersant, Zeta potential, pH value and solid phase content on the viscosity of the slurry and the effects of premix liquid concentration and solid phase content on the compressive strength, bending strength, density and shrinkage rate were studied. Through this study, The rheological properties of the slurry and the high solid content of the powders were improved. The number of green holes was reduced and ultimately the densification of products was achieved. The results show that the strength of the body is 35MPa, the density and bending strength are 99.4% and 452.18MPa, respectively. When the solid content of 62vol%, the dry shrinkage rate of the alumina ceramic body is 0-5%.The reason of the air hole in the process of gelcasting was analyzed. The mechanical properties of the vacuum mixing method, the body and the sintering body of the suspension were improved. Further, the product of weight loss, heat and chemical reaction was studied and it was found that the concentrated release of the organic material is the basic reason for the cracking of the body. On the basis of the strength of the body, the method to reduce the content of organic matter in the body is proposed to avoid the crack of casting.