4^th European Mechanics of Materials Conference on Processes, Microstructures and Mechanical Properties

J. Phys. IV France 11 (2001) Pr4-33-Pr4-40
DOI: 10.1051/jp4:2001405

Optimization of high strength materials : Design of the engineering parameters through the nanostructure characterization

L. Thilly^{1, 2}, F. Lecouturier², M. Véron³, E. Snoeck⁴, J.P. Peyrade¹ and S. Askénazy<sup>2

1</sup>  Laboratoire de Physique de la Matière Condensée (LPMC), 135 avenue de Rangueil, 31077 Toulouse, France
²  Laboratoire National des Champs Magnétiques Pulsés (LNCMP), 143 avenue de Rangueil, 31432 Toulouse, France
³  Laboratoire de Thermodynamique et Physico-Chimie Métallurgiques (LTPCM), 1130 rue de la Piscine, 38402 Saint-Martin-d'Hères, France
⁴  Centre d'Élaboration de Matériaux et d'Études Structurales (CEMES), 29 rue J. Marvig, 31055 Toulouse, France

Abstract
High strength and high conductivity conductors are elaborated via strong plastic deformation by drawing, for the winding of high pulsed magnetic field coils. These nanocomposites are composed of a copper matrix containing 9.10⁶ continuous niobium nanofilaments. The microstructure has been studied in detail using X-Ray diffraction, TEM, HREM : the niobium fibers are nanowhiskers separated from the inter-filamentary copper by semi-coherent interfaces. TEM in-situ tensile tests revealed a mechanism of single dislocation loops nucleation in the nanoscaled copper matrix. Its analytical simulation takes into account all the characteristics of the structure and is in good agreement with the experimental strength data. All these fundamental studies are combined to define the engineering parameters for the strength optimization of the nanocomposites. These parameters were applied to design the new nanocomposites. The first strength results are given for conductors containing 52.10⁶ filaments with a diameter down to 25 nm.

© EDP Sciences 2001