National Research Nuclear University “MEPhI”, Moscow, Russia:

G. K. Baryshev, Post-Graduate Student, e-mail: gkbaryshev@mephi.ru
A. P. Biryukov, Student
V. I. Surin, Assistant Professor

“Russian superconductor” JSC, Moscow, Russia:

V. I. Pantsyrnyy, Chief Development Officer

This work describes the methodology of analysis of properties of 2-phase metallic-matrix Cu – Nb composites by means of structure-sensitive methods of functional electrophysical diagnostics. The Cu – Nb composite samples had the shape of thin wires (0.2 mm in diameter and 0.2–0.5 m in length). Electrical resistance, thermoelectric power and differential contact potential difference were sequentially measured by datameasuring system. The microstructure of composite was researched at the scanning electronic microscope before the experiments were started. Electrical resistance was measured with 4-point method with further calculation of specific electric resistance and current-voltage characteristic plotting. Differential thermoelectric power of the composite was measured relatively to chromel, copper and technical nickel. The wires with diameter from 0.1 mm (Ni) to 0.23 mm (Cu) were used as comparing electrodes. In the process of contact potential measuring, there was used a mobile sensor, which makes possible to carry out measurings at various positions of the sample in conditions of straining relaxation (at given deformation value). Stepwise straining was realized at room temperature with the step height of ~10^–3 and holding time of 6–7 min. Angular rate of the stressing system reached up to ~1 degree per second. The contact potential of measuring probe was made of steel. The reference probe was taken away from the measuring base. The
Cu – Nb composite contact potential was measured at five positions at the distance of 2, 12, 22, 32 and 42 sm from the reference point, which made it possible to carry out the analysis of dynamics of changing of inherent stress along the sample.

1. GOST 6616-94. Preobrazovateli termoelektricheskie. Obshchie tekhnicheskie usloviya (State Standard 6616-94. Thermal voltage converters. General specifications). Introduced : January 01, 1999. Moscow : Publishing House of Standards, 1998.
2. Pantsyrnyy V. I., Khlebova N. E., Laushkin A. V., Medkov V. V. K voprosu o stroenii fazovykh granits razdela v obemnykh nanostrukturnykh kompozitsionnykh materialakh (About the construction of phase boundaries of section in solid nanostructure composite materials). Fizikokhimiya ultradispersnykh (nano-) sistem : sbornik nauchnykh trudov VIII Vserossiyskoy (mezhduna rodnoy) konferentsii (Physics and chemistry of ultradisperse (nano-) systems : collection of scientific proceedings of the VIII All-Russian (International) conference). Moscow, 2009. pp. 127–131.
3. Putilov A. V., Shikov A. K., Pantsyrnyy V. I., Vorobeva A. E., Drobyshev V. A. Tsvetnye Metally — Non-ferrous metals. 2008. No. 3. pp. 77–83.
4. Surin V. I., Evstyukhin N. A. Elektrofizicheskie metody nerazrushayushchego kontrolya i issledovaniya reaktornykh materialov (Electrophysical methods of non-destructive control and research of reactor materials). Moscow : MEPhI, 2008.
5. Frank J. Blatt, Peter A. Schroeder, Carl L. Foiles, Denis Greig. Termoelektrodvizhushchaya sila metallov (Thermoelectric power of metals). Moscow : Metallurgiya, 1980.
6. Peletskiy V. E., Belskaya E. A. Elektricheskoe soprotivlenie tugoplavkikh metallov : spravochnik (Electric resistance of refractory metals : reference book). Moscow : Energoizdat, 1981.
7. Belevtsev A., Bogatov V., Karzhavin A., Petrov D., Ulanovskiy A. Termoelektricheskie preobrazovateli temperatury. Teoriya, praktika, razvitie (Thermoelectric temperature converters. Theory, practice, development). Sovremennye tekhnologii avtomati zatsii — Contemporary Technologies in Automation. 2004. No. 2. Available at : www.cta.ru.
8. Poverkhnostnye svoystva tverdykh tel (Surface properties of solid bodies). Under the editorship of M. Grin. Translated from English under the editorship of V. F. Kiselev. Moscow : Mir, 1972.
9. Kravchenko V. Ya. Fizika tverdogo tela — Physics of solid state. 1967. Vol. 9, Iss. 4. pp. 1050–1057.
10. Berestetskiy E. M., Lifshits L. P., Pitaevskiy L. P. Kvantovaya elektrodinamika (Quantum electrodynamics). Moscow : Nauka, 1989.
11. Surin V. I., Evstyukhin N. A., Cheburkov V. I. Osobennosti poverkhnostnoy deformatsii materialov : sbornik nauchnykh trudov (Peculiarities of surface deformation of materials : collection of scientific proceedings). Nauchnaya sessiya MIFI-2005 (Scientific session MEPhI-2005). Moscow : MEPhI, 2005. Vol. 9. pp. 90–91.
12. Zuev L. B., Barannikova S. A., Zavodchikov S. Yu. Fizika metallov i metallovedenie — The Physics of Metals and Metallography. 1999. Vol. 87, No. 3. pp. 77–79.
13. Panin V. E., Pleshanov V. S., Burkova S. A., Kobzeva S. A. Materialovedenie — Materials Science. 1991. № 8/9. pp. 22–27.