Synthesis
WC can be prepared by reaction of tungsten metal and carbon at 1400–2000 °C. Other methods include a patented fluid bed process that reacts either tungsten metal or blue WO3 with CO/CO2 mixture and H2 between 900 and 1200 °C. WC can also be produced by heating WO3 with graphite in hydrogen at 670 °C following by carburization in Ar at 1000 °C or directly heating WO3 with graphite at 900 °C. Chemical vapor deposition methods that have been investigated include:
- reacting tungsten hexachloride with hydrogen, as a reducing agent, and methane, as the source of carbon at 670 °C (1,238 °F)
- WCl6 + H2 + CH4 → WC + 6 HCl
- reacting tungsten hexafluoride with hydrogen, as reducing agent, and methanol, as source of carbon at 350 °C (662 °F)
- WF6 + 2 H2 + CH3OH → WC + 6 HF + H2O
Read more about this topic: Tungsten Carbide
Famous quotes containing the word synthesis:
“If in the opinion of the Tsars authors were to be the servants of the state, in the opinion of the radical critics writers were to be the servants of the masses. The two lines of thought were bound to meet and join forces when at last, in our times, a new kind of regime the synthesis of a Hegelian triad, combined the idea of the masses with the idea of the state.”
—Vladimir Nabokov (1899–1977)
“The new shopping malls make possible the synthesis of all consumer activities, not least of which are shopping, flirting with objects, idle wandering, and all the permutations of these.”
—Jean Baudrillard (b. 1929)
“The invention of photography provided a radically new picture-making process—a process based not on synthesis but on selection. The difference was a basic one. Paintings were made—constructed from a storehouse of traditional schemes and skills and attitudes—but photographs, as the man on the street put, were taken.”
—Jean Szarkowski (b. 1925)