Name: titanium carbide

English name: Titanium carbide

CAS No.: 12070-08-5

Crystal form: 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

Thermal conductivity coefficient: 7.74 × 10-6/K

Thermal conductivity: 21 w/(m? K)

Heat of generation: 183.4kJ/mol

Room temperature resistance: 60 μ Ω

Solubility: soluble in nitric acid and aqua regia, insoluble in water,. It is stable to the air when it is below 800 ℃, eroded by the air when it is above 2000 ℃, and can react with pure O2 at 1150C.

Synthesis method:

Carbothermal reduction method:

The mixture of titanium powder and carbon obtained from the reduction of TiO2 by hydrogen acts at high temperature, or the mixture of TiO2 and carbon powder is pressed into a block, and then heated to 2300-2700 ℃ in an electric furnace and carbonized in H2 or CO atmosphere. Purpose: making cemented carbide, also used as electrode and abrasive for arc lamp. Reduce TiO2 with carbon black, the reaction temperature range is 1700-2100 ℃, and the chemical reaction formula is: TiO2 (s)+3C (s)=TiC (S)+2CO (g).

Direct carbonization method:

TiC is formed by the reaction of Ti powder and carbon powder. The chemical reaction formula is Ti (s)+C (s)=TiC. Because it is difficult to prepare submicron metal Ti powder, the application of this method is limited. The above reaction takes 5-20 hours to complete, and the reaction process is difficult to control. The reactants are seriously agglomerated. Further grinding is required to prepare fine TiC powder. In order to obtain more pure products, it is necessary to purify the fine powder after ball milling by chemical methods.

Purpose:

Use of titanium carbide

1. Application of nanometer titanium carbide in aerospace components

It has a melting point above 3000 ℃, good high temperature strength, good compatibility with tungsten, similar coefficient of thermal expansion, and much lower density than tungsten.

2. Nano titanium carbide foam ceramics

As a filter, foam ceramic can effectively remove inclusions in various fluids, and its filtering 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 this type of material is mostly oxide. In order to adapt to the filtration of metal melt, the main goal is to improve the thermal shock resistance. Nano titanium carbide foam ceramics have higher strength, hardness, heat conduction, conductivity, heat resistance and corrosion resistance than oxide foam ceramics;

3. Transparent titanium carbide ceramics are widely used in many fields, such as manufacturing wear-resistant materials, cutting tools, molds, melting metal crucibles, and are good optical materials; Titanium carbide abrasive in abrasive and abrasive industry is an ideal material to replace traditional abrasive materials such as aluminum oxide, silicon carbide, boron carbide and chromium oxide; The grinding ability of nanometer titanium carbide is comparable to that of synthetic diamond, which greatly reduces the cost. At present, it has been widely used in the United States, Japan, Russia and other countries. Abrasives, grinding wheels, grinding paste and other products made of nanometer titanium carbide materials can greatly improve grinding efficiency, grinding accuracy and surface finish.

4. Powder metallurgy

Nano-titanium carbide powder is used as raw material for powder metallurgy production of ceramics and cemented carbide parts, such as wire drawing dies and cemented carbide dies.