1070-4272/05/7811-1767C2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 11, 2005, pp. 1767!1771. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 11,
2005, pp. 1801!1805.
Original Russian Text Copyright + 2005 by Perevislov, Panteleev, Ordan’yan.
AND INDUSTRIAL INORGANIC CHEMISTRY
Synthesis of Complex Tungsten!Zirconium Carbonitrides
S. N. Perevislov, I. B. Panteleev, and S. S. Ordan’yan
St. Petersburg State Technological Institute, St. Petersburg, Russia
Received September 23, 2005
Abstract-The process parameters (temperature, atmosphere, and composition) of the synthesis of complex
1 ! x
1 ! y
were determined. The area of formation of homogeneous carbonitrides in
synthesis from refractory compounds and from WC and zirconium oxide was found. The conditions of
appearance of the hemicarbide W
C were elucidated. The possibility of fabricating homogeneous carbo-
nitrides (CNs) at the lower temperature of the synthesis by increasing fineness of the starting components
by vibrogrinding was examined.
Nitrogen-containing compounds, and carbonitrides
of the Group IV3VI metals in particular, can be con-
sidered as very promising components of hard alloy
cutting tools based on tungsten carbide. Carbonitrides
occupy the intermediate place between carbides and
nitrides and possess a complex of physicochemical
properties including high hardness, high heat conduc-
tivity, and ability to sustain low-temperature micro-
plastic deformation. At the same time, they are free
from the main drawback typical of nitrides consisting
in that the angle of wetting of a metal binder with
the melts is close to zero. At the same time, the pres-
ence of nitrogen largely decreases the friction coef-
ficient and adhesion to the treated metal, which
enhances the cutter performance.
The cubic carbonitrides in a mixture with tungsten
carbide can partially dissolve it with the formation of
carbonitrides of a complex composition. Such proc-
esses should inevitably lead to the appearance of dif-
fusion porosity (Frenkel3Kirkendall effect) and result
in the deterioration of mechanical properties (bending
strength and hardness). To eliminate this drawback,
preliminary synthesis of complex carbonitrides may
be suggested. To obtain high-purity stoichiometric
preparations, it is the most reasonable to use carbides
and nitrides of tungsten and of Group IV3VI transi-
The reaction of WC with zirconium nitride and zir-
conium carbide can yield a new interstitial phase, a
solid solution of complex carbonitride (CN) of the
general formula (W
13 y3 z
designates the vacancies in the nonmetal sublattice.
For stoichiometric compositions, the area in which
such compounds can exist can be presented by the
section in the four-component system W3Zr3C3N
(Fig. 1), formed by the binary compounds WC and
WN (hexagonal crystal system), and by ZrC and ZrN
(cubic crystal system).
Tungsten nitride WN decomposes above 600oC.
This restricts the choice of compositions and makes
carbonitride synthesis feasible only for compositions
in the WC3ZrC3ZrN pseudoternary system. Thus,
the dashed line in Fig. 1 is the conventional boundary
of the area of compositions wherein the complex
carbonitrides can be synthesized from carbides and
nitrides without participation of WN.
The mutual solubility of WC and ZrC was studied
elsewhere . The results are summarized in
Data on the solubility of WC in zirconium nitride
are lacking. Zirconium carbide and zirconium nitride
form a continuous series of solid solutions over the
entire concentration range .
Fig. 1. The WC3ZrC3ZrN3WN section in the quaternary