Control of carbon loss during synthesis of WC powder through ball milling of WO3-C-2Al mixture

نویسنده:
, , , , ,
سال
: 2009
چکیده: WC–Al2O3 composite powder potentially could be synthesized through milling of WO3–C–2Al mixture.

High temperature resulted from reduction ofWO3 by Al, activates the reduction reaction ofWO3 by C and

brings about carbon deficiency in the system which consequently causes the formation of undesirable

W2C phase. Hence, addition of excess amounts of C becomes necessary. The aim of the present study

has been to find out some appropriate routes for the fabrication of WC–Al2O3 composite powder from

WO3–2Al–C mixtures in such away that the formation ofW2C is prevented. Results of high energy milling

showed that the mode of reaction inWO3–2Al–C mixture is MSR (mechanically induced self-propagating

reaction). In this system, evolution of CO gas and high value of C loss were evidences for the need of

excess C. For samples produced via suggested routes, no CO evolution was observed and the amounts of

total carbon were constant. These observations showed that the proposed routes have been capable of

producing WC phase without the presence of W2C. Mechanism of the reactions in each route has been

discussed.
کلیدواژه(گان): WC,Fabrication,Carbon loss
کالکشن :
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