The topotactic transformation of tungsten oxide to a cubic tungsten carbide

1989 ◽  
Vol 6 (3) ◽  
pp. 196-199 ◽  
Author(s):  
Jae Sung Lee
2007 ◽  
Vol 19 (21) ◽  
pp. 3682-3686 ◽  
Author(s):  
J. C. Lytle ◽  
N. R. Denny ◽  
R. T. Turgeon ◽  
A. Stein

2011 ◽  
Vol 312-315 ◽  
pp. 248-252 ◽  
Author(s):  
J. Ma ◽  
Shi Gen Zhu ◽  
H. Ding ◽  
W.S. Gu

In this work, the effects of mechanical milling on the extent of reduction were investigated to give an overview of potential improvements in the preparation of WC. A mixture of graphite and tungsten oxide (WO3) was mechanically milled together for 10 h. The as-milled powder and un-milled powder were investigated by thermal analysis, isothermal treatment, and X-ray diffraction to determine the effect of milling on the carbothermal reduction of WO3 to tungsten carbide (WC). The as-milled powder underwent a rapid reduction reaction at about 150°C lower than the un-milled powder. The reduction sequence to WC was illustrated to differ for the two powders. The milled powder showed complete reduction to WC in 1 h at 1215°C whereas the un-milled powder was incompletely reduced. Finally, WC powder was readily achieved by carbothermic reduction of mechanical activated WO3 and graphite, leaving its grains nano-sized.


2012 ◽  
Vol 510 ◽  
pp. 619-622
Author(s):  
Xiao Ming Fu

Fine cemented carbide in the diameter of less than 1 μm is obtained activated tungsten oxide. The samples are characterized by laser particle size analyze, electron microscope and sclerometer. The experimental results show that the size of tungsten particles and tungsten carbide prepared with activated tungsten becomes small remarkably, and coarse tungsten particles decrease. The properties of cemented carbide prepared with activated tungsten oxide are better than those of cemented carbide made with blue tungsten oxide. Especially, the hardness of cemented carbide prepared with activated tungsten oxide increases by about 7 %.


2013 ◽  
Vol 829 ◽  
pp. 622-626
Author(s):  
Arash Kariminejad ◽  
Behrooz Ghasemi ◽  
Milad Milani ◽  
Hassan Ghorbani ◽  
Mohammad Azadeh

Solid state carbothermic reduction of tungsten oxide (WO3) to nanosized tungsten carbide (WC) particles was achieved by heating mechanically activated mixture of tungsten oxide and graphite at different temperatures under vacuum condition. KCl and Ni were added to the mixture for some samples. The morphology and chemical composition of products, as well as particles size and their distribution were compared by X-ray diffraction and field emission scanning electron microscopy. Mechanical activation of WO3-C powder mixture did not yield WC phase whereas it was possible to produce WC nanoparticles by heating at 1250 °C for 2 h. KCl additive caused fine and homogeneous particle and Ni additive assisted the growth of WC particles.


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