Positive Temperature Coefficient is a kind of semiconductor thermal ceramics. Its characteristic is sensitive to temperature. It shows negative resistance when it is lower than the Curie temperature; when it reaches the Curie temperature, its resistance value begins to increase sharply. When used as a heating material, it has the following superior characteristics: automatic constant temperature, no oxygen consumption, corrosion resistance, etc. PTC ceramics are mainly doped barium titanate semiconductor ceramics, which have relatively small ionization energy and can be thermally excited to generate conductive carriers at room temperature, thereby forming semiconductors.
Zirconia precision ceramic material has the characteristics of high temperature resistance, chemical corrosion resistance, oxidation resistance, wear resistance, large thermal expansion coefficient, small specific heat and thermal conductivity, and toughening characteristics after stabilization. The following Kezhong Ceramics is good for everyone Introduce the compressive strength and flexural strength of zirconia precision ceramics at high temperature.
With the development of materials science and the improvement of people's aesthetic awareness, all-ceramic restorations have been widely used because of their good aesthetic properties. Zirconia ceramic restorations have gradually become the first choice for restoration of posterior tooth defects due to their good mechanical properties, biocompatibility, less impact on the results of radiological medical examinations, and less wear on the natural teeth of the opposite jaw.
Alumina ceramic materials generally have fairly large elastic modulus, high hardness, high brittleness, and strong crack sensitivity. Therefore, alumina ceramics have certain processing difficulties. What should be paid attention to during the processing.
How alumina ceramics beat metalThe new generation of industrial parts is alumina ceramics, which will replace traditional metal parts, because ceramics have good performance and high availability, which can further improve the performance of the machine.High-purity alumina ceramics can be made into
Ceramics have a variety of excellent characteristics. When used in automobiles, they can effectively reduce the weight of the vehicle, increase the thermal efficiency of the engine, reduce fuel consumption, reduce exhaust pollution, increase the life of wearing parts, and improve the intelligent functions of the car. Therefore, the development and application of ceramic parts in automobiles has very broad prospects.
Ceramic sealing ring is widely used in all aspects of our life. Because of its high-performance electrical sealing system adopts ceramic sealing ring, it has excellent heat resistance, mechanical shock and corrosion performance. It is often used in electrical sealing system, and because of its excellent corrosion resistance and biological Compatibility is commonly used in medical implant devices such as fibrillators, cochlear implants and neurostimulators. The excellent resistance to high temperature, vibration and mechanical shock is often used in aerospace such as aircraft engines, fire detection systems, etc.
Each of the factors will affect the firing of zirconia ceramics, as well as several main factors affecting the firing of zirconia ceramics: degreasing stage, raw powder, additives, sintering temperature and time, pressure and sintering atmosphere.
The application of rare earths and rare earth oxides in ceramic materials is mainly used as additives to improve the sintering, compactness, microstructure and crystal phase composition of ceramic materials, thereby greatly improving their mechanics and electrical , Optical or thermal properties to meet the performance requirements of ceramic materials used in different occasions. This article briefly reviews the application of rare earth oxides in structural ceramic materials and functional ceramics.
