New technology development direction of special ceramics
Special ceramics refer to ceramics with special mechanical, physical or chemical properties, which are used in various modern industries and cutting-edge science and technology. The raw materials used in special ceramics and the required production process are very different from ordinary ceramics, and some countries call them "precision ceramics". Recently, Chinese materials experts have agreed that it would be better to call them "advanced ceramics". Special ceramics can be subdivided into structural ceramics, functional ceramics and tool ceramics according to their performance characteristics and uses.
Special ceramics have various molding methods such as hot die casting, hot pressing, static pressure, vapor deposition, etc. These ceramics are called special ceramics or high-tech ceramics because of their chemical composition, microstructure and performance are different from ordinary ceramics. called fine ceramics.
New technology development of special ceramics : (1) In terms of powder preparation, ultra-high temperature technology is dazzling. Ultra-high temperature technology can be used not only to develop special ceramics, but also to develop new types of glass, such as magnetic glass, optical fiber, zero-expansion crystalline glass, hybrid integrated circuit board, high-strength glass, artificial bone, dental stick, etc. In addition, materials such as tantalum, molybdenum, tungsten, vanadium iron, and titanium can also be developed through ultra-high temperature technology, which can be used in cutting-edge fields such as aerospace, ocean, and nuclear fusion. Ultra-high temperature technology has the following advantages: substances that cannot be produced by conventional methods can be produced, and substances of extremely high purity can be obtained. Productivity will be greatly improved, and operating procedures will be simplified and easy. (2) Forming: The forming methods of special ceramics can be divided into two categories: dry forming and wet forming: dry forming includes ultra-high pressure forming, isostatic pressing forming, steel mold pressing forming, powder electromagnetic forming, etc.; wet forming is roughly It can be divided into plastic molding and colloid casting molding. In recent years, colloid molding and solid moldless molding technology have also achieved rapid development in the research of special ceramic molding. Colloidal ceramic molding is the wet molding of highly dispersed ceramic slurry. Compared with dry molding, colloidal ceramic molding can effectively control agglomeration and reduce defects. Moldless molding is actually the application of rapid prototyping technology in the preparation of ceramic materials. The colloidal moldless molding process of special ceramic materials is a process of directly changing the ceramic slurry with or without a binder from liquid to solid under certain conditions, and then manufacturing ceramic green bodies layer by layer according to the RPM principle. The formed green body generally has good rheological properties, which can ensure that it will not be deformed during post-processing.
The future development of special ceramic molding technology will focus on the following aspects: 1. Further develop the application of various proposed moldless molding technologies in the preparation of different ceramic materials; 3. Structural design and manufacture of large special-shaped parts; 4. Fabrication and practical application of ceramic microstructures; 5. Further develop new technologies that are non-polluting and environmentally friendly.