Recently, the scientific research team led by researcher Wang Shiwei of Shanghai Institute of silicate, Chinese Academy of Sciences, cooperated with Jiangxi zhongkete ceramic new materials Co., Ltd. to break through the key bottlenecks such as deformation and cracking of large-size ceramic blank during drying and sintering based on the spontaneous solidification molding system with independent intellectual property rights, The super large-size high-purity alumina ceramic disc with a diameter of 1010mm (Fig. 1) and the double-layer concentric high-purity alumina cylinder with an outer diameter of 200mm (Fig. 2) were successfully prepared. The main performance indexes of the material are better than those of similar foreign products.
Fig. 1 high purity alumina disk with diameter of 1010mm
Fig. 2 double layer concentric high purity alumina cylinder with outer diameter of 200mm
High purity alumina ceramic components with large size / complex shape are widely used in integrated circuit manufacturing, aerospace, deep-sea exploration and other fields, but they are very challenging. There is still a large gap between domestic high-purity alumina ceramics and foreign similar products in terms of size, performance and stability, resulting in heavy dependence on imports of large-size / complex shape high-purity alumina ceramic components for domestic high-end equipment.
Since 2003, the Wang Shiwei research team has carried out the exploration and research of a new in situ curing system, and developed a water-soluble epoxy resin polyamine gel system (ZL200610024613.4) and a spontaneous solidification molding system (ZL201110393876.3) based on nucleophilic addition polymerization. Compared with other gel systems, the organic network formed by the spontaneous solidification system is conducive to water transport, and the drying stress is more easily released. At the same time, the addition of organic matter in the system is small, the fluctuation of internal and external temperature difference in the debonding process is small, and the green body does not crack after sintering.
Since the invention of the spontaneous solidification molding system, Wang Shiwei’s research team has been committed to the engineering research of the molding technology. In July 2017, Jiangxi zhongkete Ceramic New Material Co., Ltd. was established by Shanghai Silicate Institute with spontaneous solidification system as the technical core to carry out the industrialization of large-size and high-purity alumina ceramic components. At present, the company has mastered the key technologies such as drying, debonding and high-temperature sintering of large-size / complex shaped alumina ceramic parts formed by spontaneous solidification, established a batch production line, realized batch sales, and won high praise from users in the field of semiconductor manufacturing in China.
The application of spontaneous solidification technology in the preparation of advanced ceramic materials with large size / complex shape has significant originality and advanced nature. Compared with the traditional cold isostatic pressing molding, spontaneous solidification molding does not need three heavy asset equipment such as granulation, molding and cold isostatic pressing, and the addition of organic matter is less. It is a manufacturing method with low energy consumption, low emission and low operation cost, which is in line with the national strategy of “double carbon” reaching the standard. The research was supported by the Shanghai excellent technology leader project, the general project of the National Natural Science Foundation of China, the key R & D plan project of the Ministry of science and technology, the key R & D plan project of Jiangxi Province and the regional key project of the STS plan of the Chinese Academy of Sciences.