COMPOZITES AND MULTIPURPOZE COATINGS | |
ArticleName | Methods of research of electrophysical service properties of smart materials on example of Cu – Nb composites |
ArticleAuthor | Pantsyrnyy V. I., Surin V. I., Baryshev G. K., Biryukov A. P., Varyatchenko E. P. |
ArticleAuthorData | “Russian superconductor” JSC V. I. Pantsyrnyy, Chief Development Officer
National Research Nuclear University “MEPhI”, Moscow, Russia V. I. Surin, Assistant Professor G. K. Baryshev, Teaching Assistant, Post-Graduate Student, e-mail: gkbaryshev@mephi.ru A. P. Biryukov, Post-Graduate Student, Engineer E. P. Varyatchenko, Senior Lecturer of a Chair |
Abstract | This paper describes the methods of research of service properties of two-phase metal-matrix Cu – Nb composites (belonging to the smart materials), by means of structure-sensitive methods of functional electrophysical diagnostics. The samples of Cu – Nb composites were shaped as fine wires (0.2 mm diameter and 0.2–0.5 m length). Electric resistance and differential contact potential difference were measured by means of information-measurement system. During the contact potential difference research, there was used the mobile sensor, carrying out the measurements in various sample spots in stress relaxation conditions (with the given strain value). Stepwise strain was carried out with room temperature. Measurements of contact potential difference of composites were carried out in five operating sites at a distance of 2, 12, 22, 32 and 42 cm from the origin, which allowed to research the dynamics of internal stresses change along the full length of the sample. Results of measurement of specific electric resistance were analyzed according to the integrated conductivity theory. There were compared the time dependences of differential contact potential difference for copper and Cu – Nb composite, measured in the spots, corresponding to the middle of the samples' length. Significant increasing of signal amplitude at the strain level of ~0.012 was the peculiarity of Cu – Nb composite testings. Experimental results confirm the suppose about fractal nature of plastic strain mechanism at mesoscopic and macroscopic levels. Internal stresses, appearing during the Cu – Nb composite wire sample testings, are distributed by more than four times inhomogeneously than the same stresses, appearing during the copper sample testings. High degree of strain strengthening in Cu – Nb leads to stress relieving with formation of surface strain waves. |
keywords | Smart materials, Cu – Nb composites, method of research of service properties, functional electrophysic diagnostics, differential contact potential difference, electric resistance, electrophysic properties of wires, information-measurement system |
References | 1. 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 in solid nanostructure composite materials). Fizikokhimiya ultradispersnykh (nano-) sistem : sbornik nauchnykh trudov VIII Vserossiyskoy (mezhdunarodnoy) konferentsii (Physics and chemistry of ultradisperse (nano-) systems : collection of scientific proceedings of the VIII All-Russian (International) conference). Moscow, 2009. pp. 127–131. |
Language of full-text | english |
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