ISSN 1067-8212, Russian Journal of Non-Ferrous Metals, 2008, Vol. 49, No. 5, pp. 428–432. © Allerton Press, Inc., 2008.
Original Russian Text © V.Ya. Bulanov, V.A. Krashaninin, S.A. Oglezneva, 2008, published in Izvestiya VUZ. Poroshkovaya Metallurgiya i Funktsional’nye Pokrytiya, 2008,
No. 5, pp. 50–55.
428
The most important task in developing new pow-
dered materials with improved physicochemical and
mechanical properties is predicting the modes of
obtaining the new composites. The development and
application of computer simulation programs allow one
to considerably simplify and accelerate the selection of
optimal production processes, shorten the number of
full-scale studies, and save power and material
resources.
The purpose of this work was to develop physico-
chemical models of the homogenization of binary
metal–metal systems, their mathematical description,
to develop computer software with visualization to sim-
ulate homogenization processes, and to verify the ade-
quacy of the developed models. The objects of investi-
gation were the powdered systems previously obtained
by mechanical alloying. Complex theoretical and
experimental investigations of homogenization pro-
cesses of the particles in solid nanosystems of transition
elements such as Fe–Mo, Fe–Cu, Fe–Ni, and Fe–Cr
performed previously allowed researchers to establish
the analytical dependences of the degree of homogeni-
zation on the time and temperature of the sintering pro-
cess [1–13]. These results are of self-dependent scien-
tific interest and are used in this work for predicting the
physicochemical and mechanical characteristics of
powdered bodies.
In investigating the properties of studied powdered
materials (depending on the composition, temperature,
and sintering time) we fabricated experimental samples
from the particles of the powders of host substances of
100–200 μm in size and doping components (80–
110 nm) by two-side pressing in rigid press molds. To
simulate the processes of diffusion interaction of com-
ponents, we selected the method of diffusion pairs. Dif-
fusion of iron and doping elements was studied for the
Fe–Me model pairs, where Me = Mo, Ni, Cu, Cr. The
samples were prepared by two methods, namely, by
pressing in the cast rod of Armco iron into the powder
of doping components or by the joint formation of the
PZhR 3.200.28 iron powder with a specified amount of
powder of doping elements in the center of the sample
1 mm in diameter. Then we performed high-tempera-
ture annealing at 1050, 1150, 1200, and 1250°C in
hydrogen and vacuum for 0.5–5.0 h. Metallographic
sections were prepared in the plane normal to the start-
ing boundary between the components of the pair. New
analytical procedures were developed, and an S4
EXPLORER X-ray fluorescent analyzer was used.
Duration of homogenization is mainly determined
empirically, and no reliable models providing its estab-
NANOSTRUCTURED MATERIALS
AND FUNCTIONAL COATINGS
Homogenization of Doping Elements
in the Fe–Mo, Fe–Cu, Fe–Cr, and Fe–Ni Nanosystems Depending
on the Sintering Time and Temperature
V. Ya. Bulanov
a
*, V. A. Krashaninin
a
**, and S. A. Oglezneva
b, c
***
a
Institute of Metallurgy, Ural Branch, Russian Academy of Sciences, ul. Amundsena 101, Yekaterinburg, 620016 Russia
b
Perm State Technical University, Komsomol’skii pr. 29-a, Perm, 614600 Russia
c
Scientific Center of Powder Material Science, Perm State Technical University, ul. Prof. Pozdeeva 6, Perm, 614013 Russia
*e-mail: bulanov27@mail.ru
**e-mail: krash@ural.ru
***e-mail: osa@pm.pstu.ac.ru
Abstract—This work is devoted to the solving a major problem of powder material science, specifically, pre-
diction of the structural and phase composition during obtaining the new multicomponent materials using the
mathematical description and development of computer software to simulate the homogenization processes of
metal–metal binary systems. The processes of homogenization in solid nanosystems of the metals of type Fe–
Mo, Fe–Cu, Fe–Ni, and Fe–Cr transition elements were investigated. A complex theoretical investigation of the
homogenization of the particles in solid nanosystems is performed, analytical dependences of the degree of
homogenization on the time and temperature of the sintering process are established, interdiffusion coefficients
in the systems are calculated, physicochemical models of homogenization are suggested, and ways that a com-
puter can analyze numerically with visualization of studied processes are developed. An evaluation of the con-
vergence of the used numerical methods is performed, the accuracy of the calculations is evaluated, and an esti-
mation of the calculations for the systems under consideration is carried out. The obtained results allow one to
reduce the number of natural experiments in the development of new materials with specified properties.
DOI: 10.3103/S1067821208050210