ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 3, pp. 258−264. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © A.A. Shubin, A.V. Sidorak, V.V. Ivanov, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 3, pp. 292−297.
INORGANIC SYNTHESIS AND INDUSTRIAL
Materials of interrupting electric contacts in low-
voltage equipment are usually heterogeneous composites
based on metal matrix (silver or copper) with additives
that provide the necessary operational characteristics.
Some metals forming pseudoalloys with metal support
as well as oxides refer to such additives . Cadmium,
zinc, and tin oxides are most widely used for silver and
copper electrical contacts. A high degree of uniformity
of distribution of heterogeneous additive in the the metal
matrix and reliable adhesive contact of phases are im-
portant factors in long-term, sustainable use of contact
elements of electrical device. Powder metallurgy is com-
mon technology of manufacturing electrical contacts. It
ensures adequate uniform distribution of components but
requires signiﬁ cant power and time consuming. Reduc-
tion of this consumptions can be realized by changing
Going from a long-term mechanical mixing of charge
components to the chemical processes of its formation,
for example, by precipitation from solutions of thermally
unstable precursors and their subsequent thermolysis al-
lows improving product quality due to better uniformity
of distribution of the oxide phase and reducing produc-
tion costs. Such a technology effectively used for contact
materials based on silver, in particular Ag/CdO [2, 3].
Therewith for electrical contact materials based on copper
said technology is not of wide application.
Enhancement of electrocontact material performance
can be provided also by improving electrical conductiv-
ity of the oxide phase. Although the applied CdO, ZnO,
possess a relatively high conductivity they are
inferior to complex oxides based on thereof. Application
of complex compounds of the system ZnO–CdO–SnO
and their additional doping by impurities to improve
the conductive properties are expedient to improve the
functional characteristics of electrical contact material.
In the system ZnO–CdO–SnO
several compounds are
[4, 5]. The ternary oxides Zn
are the most
interesting in this application and are the least studied.
They are characterized by a low resistivity (for example,
= 1.41 × 10
Ohm m) and thermal
stability up to temperature 1473 K . Synthesis of these
complex oxide inclusions in silver or copper matrix of
electrical contact in situ directly in the process of sintering
of powder product is assumed technologically promising
and of great practical importance .
Synthesis of Complex Oxides CdO
for Electrical Contacts
A. A. Shubin, A. V. Sidorak, and V. V. Ivanov
Siberian Federal University, pr. Svobodnyi 79/10, Krasnoyarsk, 660041 Russia
Rceived January 9, 2014
Abstract—A comparison of the results of synthesis of complex oxides system (2–x)ZnO–xCdO–SnO
out from various precursors at the temperature modes characteristic of the traditional method of production of
electrical contacts. Samples were synthesized from mechanical blends of powders ZnO, CdO, SnO
, and by
a method based on obtaining a mixture of precursors by co-precipitation of thermally unstable compounds. Solid
phase synthesis in such mixtures proceeds much more effectively. After heat treatment at 1123 K for 2 hours
a yield of a ternary oxide phase, in particular Zn
, is up to 93% using the co-precipitation method,
while the mechanical mixture does not allow producing these phases in signiﬁ cant quantities under the same
conditions of the synthesis.