Superman in ceramics——Carbide ceramics

(Superman in ceramics——Carbide ceramics)

Ceramic materials have been applied to various aspects of our lives. Ceramic materials are a class of inorganic non-metal materials made of natural or synthetic compounds after being shaped and sintered at high temperatures. It has the advantages of high melting point, high hardness, high abrasion resistance, oxidation resistance, etc.. It can be used as structural materials, tool materials, etc. Since ceramic also has some unique properties, it can also be used as a functional material. With the progress of society, people have higher and higher requirements for materials, and this performance is not only reflected in the field of science but also the area of people's lives. The progress of materials has mostly promoted the development of society, which in turn has helped the growth of materials science. In the case of ceramic materials, ceramic materials have penetrated the history of human development. They have continued to develop with the progress of history, temporarily emerging in the field of materials science.

Ceramic materials can be divided into ordinary ceramic materials and unique ceramic materials. Everyday ceramic materials are sintered from natural materials such as feldspar, clay, and quartz, and are conventional silicate materials. Ordinary ceramics have rich sources, low cost, and mature technology. This ceramic material can be divided into daily-use ceramics, building ceramics, electrical insulation ceramics, and chemical ceramics according to their performance characteristics and uses. Unique ceramic materials are made of high-purity synthetic raw materials, formed by precise control technology and sintered, and generally, have specific unique properties to meet various needs. According to their raw material components, they can be divided into carbide ceramics, oxide ceramics, nitride ceramics, and cermets. Unique ceramics have select mechanical, acoustic, optical, electrical, magnetic, thermal, and other properties, and they are also widely used.

Let us focus on the carbide ceramic materials. Carbide ceramics are ceramics containing carbon, poorly soluble compounds as the main component. One is a metal-like carbide such as titanium carbide, zirconium carbide, tungsten carbide, etc .; one is a non-metal carbide, such as carbon tetraboride, silicon carbide, and the like. Carbide is a high-temperature resistant material. Many of these carbides have melting points above 3000 ° C. Most carbides are more resistant to oxidation than carbon and graphite. Many carbides have high hardness and excellent chemical stability. Carbide ceramics also have unique properties such as high heat resistance and high hardness. Carbide ceramics are widely used as heat-resistant materials and super hard tools.

Among the high-temperature carbide structure, ceramic materials, silicon carbide ceramics, boron carbide ceramics, and titanium carbide ceramics are the three most important materials and are used most widely.

1. Silicon carbide has a diamond crystal structure and has strong covalent bonds. Silicon carbide ceramic has high hardness, good strength, high thermal conductivity, and excellent oxidation resistance. It can be used in high temperature, high pressure, strong acid, strong alkali, and high-temperature oxidation environments. It is widely used in the petroleum industry, chemical industry, and energy industry. It is also used in the fields of machinery, mining, papermaking, steelmaking, nuclear sector, microelectronics industry, and lasers.

2. The hardness of boron carbide is second only to diamond and cubic boron carbide in nature. In particular, the nearly constant high-temperature hardness is unmatched by other materials, so it has become an essential member of the superhard material family. Boron carbide has a high melting point, high hardness, high modulus, small capacity, abrasion resistance, acid, and alkali corrosion resistance, etc., and has good neutron and oxygen absorption capabilities, has a lower coefficient of expansion, excellent thermoelectric properties, is A relevant structural ceramic material. Boron carbide ceramic is an advanced excellent grinding material, which can be used for grinding, grinding, drilling, and polishing of hard materials such as gems, ceramics, tools, bearings, hard alloys, etc. Boron carbide ceramics are the first choice for industrial ceramic materials, Widely used in sandblasting machinery, electronics, information, aerospace, automotive and other industries; boron carbide ceramics have large thermal neutron capture cross-sections, have excellent neutron absorption and radiation resistance, and can be used as shielding and control materials Is the safety guarantee of the nuclear industry; boron carbide ceramics have high strength and small specific gravity, and are particularly suitable for use in bullet-proof armor, such as the protection of aircraft, vehicles, ships, and human bodies; boron carbide ceramics have the characteristics of anti-oxidation and high-temperature resistance. As advanced shaped and amorphous refractories are widely used in metallurgical fields; boron carbide ceramics have stable chemical properties, do not react with acids and alkalis, and have high synthetic positions, so they are widely used in the production of other boron-containing materials, such as bosonization Titanium, zirconium boride, etc .;

3. Titanium carbide ceramic has high strength, good thermal conductivity, high hardness, excellent chemical stability, no hydrolysis, good high-temperature oxidation resistance, and does not react with acids at room temperature. Titanium carbide ceramics are essential raw materials for hard alloys; transparent titanium carbide ceramics are right optical materials; porous titanium carbide ceramics can be used as high-temperature-resistant materials and used to make filters and photocatalytic materials when the porosity of titanium carbide ceramics is 50%, Great for artificial bones.

(Superman in ceramics——Carbide ceramics)