TITANIUM NITRIDE SYNTHESIS IN THE PRESENCE OF IODINE
S. P. Bogdanov
Translated from Novye Ogneupory, No. 5, pp. 48 – 51, May 2015.
Original article submitted March 26, 2015.
A method is proposed for synthesizing titanium nitride by nitriding titanium metal powder with nitrogen in the
presence of iodine vapor, and results are given for its application. It is shown that iodine significantly reduces
the nitriding reaction activation energy. It is established that TiN forms even at 250°C. It is detected that the
size of TiN crystal blocks formed depends on temperature. A nitriding mechanism is proposed.
Keywords: titanium nitride, nitriding, iodine, iodide transport, crystal structure parameters.
It is well known that titanium forms several phases with
nitrogen. It has been established that the limiting solubility of
nitrogen in a-Ti is about 17 at.%. Two nitrides have been de-
N and TiN, exhibiting a broad homogeneity range.
The lower limit of the homogeneity range for TiN phase, ac-
cording to estimates of different authors, lies in the range
10.0 – 14.8 wt.% (TiN
). A nitrogen content of
50 at.% is taken as the upper limit . Results of X-radio-
graphic studies have shown that as nitrogen content increases
in the TiN homogeneity range there is a change in crystal lat-
tice parameter. Different dependences are encountered in
publications for parameter a on Ni/Ti ratio. Parameter a of
the crystal lattice with a change in nitrogen content from 0.42
to 1 against stoichiometry increases from 0.4212 to
0.4234 nm according to data in , or from 0.4218 nm to
0.4241 nm according to data in .
Titanium nitride exhibits a high melting temperature,
good chemical stability, and develops good corrosion resis-
tance in aggressive metal and oxide melts . Being quite a
hard and wear resistant material TiN is used in the produc-
tion of cutting tools. TiN powder is used for sintering tung-
sten-free hard alloys, and it is used in composite materials
based on cubic boron nitride. Superconducting and thermo-
electric composites and material for readioelectronics are
composed from TiN . A composite of titanium nitride and
chromium is recommended as high-resistance material. Po-
rous TiN, prepared by powder metallurgy, is used as an insol-
uble anode during electrolysis of aqueous salt solutions .
The main methods for preparing TiN powder are
nitriding titanium metal and its hydride; reaction in a gas
phase between TiCl
and ammonia or mixtures of nitrogen
and hydrogen; decomposition of titanium aminochloride and
other similar compounds, containing titanium and nitrogen;
reduction of TiO
by carbon or metal in a nitrogen atmo-
sphere. Nitriding titanium metal was first carried out in 1831.
It has been established that up to 500°C nitrogen does not act
on titanium, and absorption commences at 500 and at 800°C
it develops energetically with formation of TiN. Total com-
pletion of diffusion with nitride formation of limiting compo-
sition is achieved with exposure for2–4hat1200°C [1, 6].
In publications [7 – 10] it has been demonstrated that
presence of iodine vapor is capable of reducing significantly
the chemical reaction temperature for titanium with a num-
ber of substances. The aim of the present work is to study
nitriding of titanium metal powder with nitrogen in the pres-
ence of iodine vapor.
The starting materials used in the work were titanium
powder with a grain size of 5 – 35 mm, metallic iodine, and
high purity nitrogen. Preliminary calculations by means of a
Thermain program showed that at any temperature in the
range 20 – 1000°C the stable phase in the Ti–N system is ti
tanium nitride. It follows from thermodynamic calculations
that the high-temperature (>800°C) parameters described in
publications for preparing TiN are a consequence not of ther
Refractories and Industrial Ceramics Vol. 56, No. 3, September, 2015
1083-4877/15/05603-0267 © 2015 Springer Science+Business Media New York
FGBOU VPO St. Petersburg State Technological University, St.