Name | Tungsten carbide |
Synonyms | HSDB 2932 Tungsten carbide tungsten(+4) cation |
CAS | 11130-73-7 12070-12-1 |
EINECS | 235-123-0 |
InChI | InChI=1S/C.W |
Molecular Formula | C.W |
Molar Mass | 195.85 |
Melting Point | 2870℃ |
Boling Point | 6000℃ |
Appearance | Black crystal |
Storage Condition | Room Temprature |
MDL | MFCD00011464 |
There are two types of tungsten carbide: wzC and wc. W2C is a black hexagonal crystal with a relative density of 17. 15, a melting point of 2800 ° C, a lattice constant of 0. 29982nm,c-0.4722nm. wc is a gray hexagonal crystalline powder. Relative density 15. 63, melting point 2870 ℃, lattice constant a = 0. 29063nm,c-0.28386nm. Boiling point 6000 °c. Thermal conductivity 121W/(m.K). Coefficient of thermal expansion: 100 ° C. 0.104 × 10-6/K,200 ° C. 0. 236 x 10-6/K,400 C 0.507 x 10-6/K,800 C 1.103 x 10-6/K,1200 C 1. 768*10-6/K, Mohs hardness 9. Insoluble in water, soluble in nitric acid and hydrofluoric acid mixed acid. Strong acid resistance. High hardness. The elastic modulus is high.
with tungsten and carbon as raw materials, tungsten powder with an average particle size of 3-5uM and carbon black in an equal amount are dry mixed with a ball mill, after pressure molding, the graphite pan is placed in the graphite pan, and the graphite pan is heated to 1400 to 1700 ° C., preferably 1550 to 1650 ° C. In a graphite resistance furnace or an induction furnace. In the hydrogen stream, W2C is initially generated and the reaction continues at elevated temperatures to form wc. Or first put the six carbonyl tungsten [W(CO).] Tungsten powder was prepared by thermal decomposition at 650~1000 ℃ in CO atmosphere, and then reacted with carbon monoxide at 1150 ℃ to obtain wc. W2 C can be generated at a temperature higher than this temperature.
used in the manufacture of cutting tools, wear-resistant parts, copper, cobalt, bismuth and other metal melting crucibles, wear-resistant semiconductor thin films.
exposure to tungsten carbide dust can lead to gastrointestinal dysfunction, renal irritation, and upper respiratory tract inflammation. Tungsten carbide causes a proliferative response of the lymphoid tissue cells of the lung, with progressive sclerosis. The maximum allowable concentration of tungsten carbide is 6mg/m3. In the United States, the maximum allowable concentration of the soluble tungsten compound (in terms of tungsten) is 1 mg/m3, and the insoluble tungsten compound (in terms of tungsten) is 5mg/m3. Staff should be protected to prevent dust leakage. Products should be stored in a cool, dry warehouse, transport should pay attention to the packaging containers in good condition, anti-rain and anti-sun exposure.
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |