Вольфрам карбид химические свойства, назначение, производство
Химические свойства
Gray powder. Mohs hardness of 9+ in solid form. Insoluble
in water but readily attacked by a nitric acid–
hydrofluoric acidmixture. Stable to 400C with chlorine,
burns in fluorine at room temperature, oxidizes
on heating in air.
Физические свойства
Gray powder, dissolved by HF=HNO3 mixture. Cutting tools, wear-resistant semiconductor
film. Corroded by molten metals
Mg, Al, V, Cr, Mn, Ni, Cu, Zn,
Nb, and Mo. Corrosion resistant
to molten Sn and Ta.
Использование
Tungsten carbide is extremely hard and are excellent cutting materials. It is used extensivly in the tool and die industry for drilling and cutting tools, sand blasting nozzels, armor-piercing bullets, and studs to increase traction of tires.
Besides, it is used in dental burs, surgical instruments, wear-resistant coatings; in manufacture of cemented carbide; Substitute for noble metals in catalysis.
Определение
A ditungsten carbide, W2C, with similar physical
properties is also known. WC is said to be the
strongest of all structural materials.
Опасность
Toxic by inhalation.
Промышленное использование
Tungsten carbide with a 3 to 20% matrix ofcobalt is the most common structural RHM. Thelow-cobalt grades are used for applicationsrequiring wear resistance; the high-cobalt gradesserve where impact resistance is required.
Профиль безопасности
Chronic inhalation
causes lung damage in humans. Ignites at
600°C in nitrogen oxide atmospheres.
Violent reaction with F2, ClF3, NOx, IF5,
PbO2, NO2, N20. See also TUNGSTEN
COMPOUNDS.
Вольфрам карбид препаратная продукция и сырье
сырьё
препарат