Name: Titanium carbide
English name: Titanium carbide
Molecular formula :TiC
CAS number: 12070-08-5
Crystal type: cubic crystal system
Relative density: 4.93
Melting point: 3140℃
Boiling point: 4820℃
Molecular weight: 59.89
Mohs hardness: 9 ~ 10,
Microhardness: 3000kg/mm2
Elastic modulus: 2940 N/mm2
Bending strength: 240 ~ 400 N/mm2
Heat transfer coefficient: 7.74×10-6/K
Thermal conductivity: 21 w/(m? K)
Heat of formation: 183.4kJ/mol
Room temperature resistance: 60μΩ
Solubility: soluble in nitric acid and aqua regia, insoluble in water. It is stable to air at less than 800℃, corroded by air at higher than 2000℃, and can react with pure O2 at 1150C.
Application: Titanium carbide powder is used in high temperature resistant thermal spraying materials, welding materials, hard film materials, military aviation materials, hard alloy and cermet. As an additive for making thermistor, improve resistance.
Synthesis method:
Carbothermal reduction method:
The mixture of titanium powder and carbon obtained from the reduction of TiO2 by hydrogen is acted at high temperatures, or the mixture of TiO2 and carbon powder is pressed into blocks, and then heated to 2300-2700℃ in an electric furnace and carbonized in H2 or CO atmosphere. Uses: carbide, also used as arc lamp electrode and abrasive. TiO2 is reduced with carbon black, the reaction temperature range is 1700-2100℃, the chemical reaction formula is: TiO2(s)+3C(s)=TiC(S)+2CO(g).
Direct carbonization method:
TiC was formed by the reaction of Ti powder and carbon powder. The chemical formula is: Ti(s)+C(s)=TiC. Because it is difficult to prepare submicron metal Ti powder, the application of this method is limited, and the reaction takes 5-20 hours to complete, and the reaction process is difficult to control, and the reactants are seriously agglomerated, requiring further grinding processing to prepare fine granular TiC powder. In order to obtain a purer product, the fine powder after ball milling needs to be purified by chemical methods.
Purpose:
The use of titanium carbide
1. Nano titanium carbide is used in aerospace components
It has a melting point above 3000 ℃, has a good high temperature strength, and has good compatibility with tungsten, similar thermal expansion coefficient, and has a much lower density than tungsten.
2. Nano titanium carbide foam ceramics
As a filter, foam ceramics can effectively remove the inclusions in various fluids, and the filtration mechanism is agitation and adsorption. The filter requires the chemical stability of the material, especially the filter used in the metallurgical industry requires a high melting point, so such materials are mostly oxide, and in order to adapt to the filtration of metal melt, the main pursuit of thermal shock resistance. Nano-titanium carbide foam ceramics have higher strength, hardness, thermal and electrical conductivity, heat and corrosion resistance than oxide foam ceramics.
3. Widely used in the manufacture of wear-resistant materials, cutting tools, molds, melting metal crucible and many other fields of transparent titanium carbide ceramics is a good optical material; Abrasives and abrasives Industry Titanium carbide abrasives are ideal materials to replace traditional abrasive materials such as alumina, silicon carbide, boron carbide, chromium oxide, etc. Nanometer titanium carbide grinding capacity can be comparable to artificial diamond, greatly reducing the cost, currently in the United States, Japan, Russia and other countries have been widely used. The abrasive, grinding wheel and grinding paste made of nano titanium carbide material can greatly improve the grinding efficiency, improve the grinding precision and surface finish.
4. Powder metallurgy field
Nano titanium carbide powder is used in powder metallurgy to produce raw materials for ceramics and cemented carbide parts, such as wire drawing dies and cemented carbide dies.
