E. G. Valova-Zaharevskaya, I. L. Deryagina, E. N. Popova, N. E. Khlebova, V. I. Pantsyrny

SPECIAL CHARACTERISTICS OF THE MICROSTRUCTURE OF HIGH-STRENGTH MULTIFILAMENTARY Cu-18Nb COMPOSITES

The paper presents refined data on the macroscopic and microscopic stresses according to X-ray diffraction analysis in multifilamentary Cu-18Nb composites fabricated by the melt-and-deform (in-situ) route, with a true strain e of 10.2 and 12.5. Under large plastic deformation by cold drawing, Nb dendrites in the Cu matrix acquire the shape of ribbons with the thickness decreasing to below 100 nm with increasing strain. The sharp fiber texture <110>Nb || <111>Cu || DA (deformation axis) develops in the composites, and its degree grows with increasing strain. The Nb crystal lattice is distorted due to the partially coherent character of the Cu/Nb interfaces, and these distortions also increase with strain. They are manifested in {110}Nb interplanar spacings extended in the longitudinal sections of the composites and compressed in the cross sections. In the Cu matrix lattice distortions are also observed, though they are much less pronounced, this being attributable to the dynamic recrystallization of copper and the weakening of its texture, even when in the composite.

Acknowledgment: The work was performed on the equipment of the collective use center of IPM UB RAS within the state assignment from FASO Russia (theme Pressure, No. АААА-А18-118020190104-3), with a partial support from UB RAS (project No. 18-10-2-24).

   

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