Synthesis of WC nanopowders from novel precursors

A novel technique for production of nano-crystalline mono tungsten carbide single phase via mechanical alloying

“…The sampling has been carried out in different times (1,2,5,10,15,20,30,50,75, 100, 125 and 150 h). In order to protect materials from oxidation and undesirable reaction, the argon gas with purity of 99.99% and pressure of 250 kPa was utilized in cup of ball mill.…”

“…In addition fluid bed, self-propagating techniques, organometallic precursor, solution state and electro chemical methods have been used for production of this carbide, but each of these methods have their specific advantages and disadvantages [9]. Due to limitations for synthesizing this material by traditional methods and considering the fact that the range of WC in the phase diagram is narrow, mechanical alloying can be a suitable method for production of nano-structured WC [10]. High-energy ball milling processes are commonly known as MM single component or mechanical alloying.…”

“…Also the existence of other phases such as W 6 C 2.54 and WC 1−x is possible. Because of W 2 C is more brittle than WC, presence of W 2 C with WC can be reduced tribology properties of final materials [2,10,[12][13][14][15][16][17]. According to this phenomenon, the production of WC single phase in nano-meter scale via mechanical alloying has been tried in this paper.…”

Metal (Mo, W, Ti) Carbide Catalysts: Synthesis and Application as Alternative Catalysts for Dry Reforming of Hydrocarbons—A Review

“…In the case of the traditional industrial method, the WC powder is commercially synthesized by carbonization of W together with C at 1400-1600 • C in an atmosphere of flowing hydrogen for 2-10 h. Tungsten powder is first produced using very pure tungsten trioxide, tungsten acid (hydrated trioxide), or ammonium paratungstate (APT), and then carbonized to WC [61]. There are many studies in the literature in which powder WC was obtained by many different methods including mechanical melting [62], thermochemical reaction [63], thermal decomposition of metal complexes [64], chemical vapor deposition [65], combustion synthesis [66], or solid-state metathesis [67].…”

Precursor-based synthesis of nanosized tungsten carbide WC and WC:nCo nanocomposites

“…Evident advantages of this technique are in the possibility of mixing the components at the molecular level, con trolling the dispersity of precursor and product parti cles, decreasing temperature to 1000-1100°С, and reducing the synthesis duration. There are several vari ants of the precursor method of producing nanosized tungsten carbide powders in which tungstic acid (H 2 WO 4 ) or ammonium tungstates, for example, (NH 4 ) 2 WO 4 , (NH 4 ) 10 [4][5][6][7][8][9]. Reagent mixtures are, as a rule, homog enized in water, and the resulting mass is dehydrated and heat treated in an inert gas medium or in a vac uum.…”