ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 1, pp. 35−39. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © I.V. Nikolaenko, A.E.Krasovskaya, G.P. Shveikin, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 1, pp. 40−44.
INORGANIC SYNTHESIS AND INDUSTRIAL
Combined Method for Obtaining Ultradispersed
Powders of Vanadium Oxides and Carbide
I. V. Nikolaenko
, A. E. Krasovskaya
, and G. P. Shveikin
Institute of Solid State Chemistry, Ural Branch, Russian Academy of Sciences,
ul. Pervomaiskaya 91, Ekaterinburg, 620990 Russia
Ural Federal University named after B.N. Yeltsin, ul. Mira 19, Yekaterinburg, 620002 Russia
Received February 3, 2015
Abstract—New opportunity to synthesize nano- and ultradispersed powdered materials by combining of two
procedures, classical liquid-phase precipitation and low-temperature microwave calcination, at a rather simple
instrumentation is described. It was found in precipitation of precursors that, depending on the synthesis condi-
tions (solution pH, amount of carbon, synthesis on the vessel surface or in the solution bulk), particles of hydrated
vanadium oxide have different morphologies. It was also found that precursor powders have an insigniﬁ cant
microporosity, which is preserved in the ﬁ nal products in trace amounts upon thermal treatment of samples.
Intermediate and ﬁ nal vanadium products were synthesized in an electromagnetic ﬁ eld in a ﬂ ow of argon, their
phase composition and structure were examined in the stages of thermolysis, reduction, and carbidization, and
their lattice constants were calculated. The morphology, size, and particle size distribution in the samples under
study were determined.
Vanadium is one of the most rarely occurring
representatives of ferrous metals. The main application
ﬁ eld of this metal is the manufacture of branded steels
and cast irons. Addition of vanadium can impart high
characteristics to titanium alloy, which is so important for
the aerospace industry. The main consumer of vanadium
(up to 95% of the whole amount of manufactured metal)
is the ferrous metallurgy. Vanadium is used in fabrication
of high-speed steel, its substituents, low-alloy tool steels,
and some construction steels. Negligibly small additions
of vanadium improve the elasticity and strength of steel
by approximately 50%.
It is known that the small grain size in manufacture
of tungsten hard alloys is reached via addition of cubic
carbides to the starting powders.
Various inhibitors (VC, Cr
, TaC, NbC, etc.) are
used to block the grain growth, but vanadium carbide
has been the best candidate for addition to the starting
powders [1, 2]. Being distributed in the form of dispersed
inclusions, this compound hinders the grain growth and
improves the mechanical properties of an alloy: hardness,
strength, and wear resistance [3–5]. It has been found that
addition of only 1 wt % vanadium carbide is sufﬁ cient
for improving characteristics of an alloy. This is the
advantage of vanadium over other alloying metals.
The vanadium resources in various kinds of mineral
raw materials are rather abundant and amounts of its
manufacture will be increasing and the number of
methods and approaches will be growing.
In this communication, we suggest a new method for
low-temperature synthesis of an ultradispersed vanadium
carbide powder. This technique combines a liquid-phase
precipitation on an inert support and a low-temperature
treatment of the resulting precursor in a microwave mufﬂ e
furnace in a ﬂ ow of argon.
The already accumulated experience of application of
the given procedure in syntheses of tungsten oxides and
carbides revealed new opportunities for obtaining metal
oxides and carbides of various modiﬁ cations, depending
on the temperature and duration of thermal treatment,
and made it possible to vary the structure, size, and
morphology of particles of the substance obtained [7, 8].