Ceramic materials have their unique advantages in performance.In terms of thermal and mechanical properties, there are high temperature resistance, heat insulation, high hardness, wear resistance and so on; In terms of electrical properties, there are insulation, piezoelectricity, semiconductor, magnetism and so on; In chemistry, it has catalysis, corrosion resistance, adsorption and other functions; In biology, it has certain biocompatibility and can be used as biological structural materials.But it also has its disadvantages, such as brittleness.Therefore, the research and development of new functional ceramics is an important field in materials science.
1.Wear-resistant ceramics:Structural ceramics are an important part of new ceramics, and one of their main uses is as wear-resistant parts or components, so they are also called wear-resistant ceramics.
2.Functional ceramics:It is an important field developing rapidly in industrial ceramics.It is used as materials for integrated circuit substrates, various sensors, capacitors, piezoelectric filters, etc., accounting for about 70% of the whole industrial ceramics market.
3.Bioceramics:Bioceramics, as a medical material, has the advantages of good biocompatibility compared with metal materials and polymer materials, and is being paid attention to by medical circles.In terms of the total output value of new ceramics in the world, this kind of ceramics accounts for about 5%.At present, some achievements have been made in alumina ceramics and hydroxyapatite ceramics, and they have been applied clinically.Bioceramics is still in its infancy, and it is a new ceramic material with the most development potential.
4.Engineering ceramics:At present, there are silicon nitride (Si3N4), silicon carbide (SiC), tungsten silicide (WSi2), zirconia (Zr02), alumina (A1203), etc.These materials have the characteristics of heat resistance, high hardness, wear resistance, corrosion resistance and low relative density.If it can be used in gas turbine, the working temperature can be increased from 1100 ℃ to 1370 ℃, and the thermal efficiency can be increased from 60% to 80%.It should be an ideal engine material.But its fatal shortcoming is brittleness.Recent studies have shown that nano-scale raw materials made of various raw materials and ceramic composites with different ratios can improve toughness after sintering.This discovery has attracted many researchers and become a hot spot in international research.It is expected that the research on synthetic ceramics will make all-ceramic internal combustion engine become a reality as soon as possible.This is a new challenge in the 21st century, which will make automobile engines, jet engines, cutting tools, molds and so on look new.
5.Electrical ceramics:It is made of alumina as the main body and sintered at 1500-1900 ℃.With the performance of piezoelectric ceramics, it can realize the mutual transformation of mechanical energy and electrical energy, and can be used for piezoelectric oscillators, radio wave filters, piezoelectric transformers, communicators, sonar flaw detectors, igniters, hair dryers, etc.
6.Superhard ceramic material:Diamond is a natural" ceramic" .Synthetic diamond has entered industrial production.Because diamond is mainly carbon structure, its high temperature oxidation resistance is poor.Boron nitride material has been developed, which is second only to diamond in hardness, but has good oxidation resistance at high temperature.Diamond begins to oxidize at 800 ℃, while cubic boron nitride begins to oxidize at 1200 ℃, which makes it have a good application prospect in high temperature resistant superhard ceramic materials.
7.Thermosensitive element ceramics:Semiconductor thermosensitive ceramics (PTC) have positive temperature coefficient.When the temperature rises to the phase change temperature, the resistance increases sharply, which can be used for various temperature control elements, such as electric heaters, electric rice burners, ovens, dryers, etc.The thermal sensor ZnO-Li2O-Cr2O3-V2O5 has 90% relative humidity and 4.24 Ω resistance.It can be used in air conditioner.
With the rapid development of new ceramic materials, superconducting materials are actually a new type of ceramics.Of course, due to the special properties of ceramic materials, when studying and developing their application prospects, different disciplines need to cross and explore new functional materials together.

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