Microstructures and textures of a Cu-Ni-Si alloy processed by high-pressure torsion

Experiments were conducted to evaluate the evolution of microstructure and texture in a commercial Cu-2.5% Ni-0.6% Si (wt.%) alloy during processing by high-pressure torsion (HPT) at room temperature up to a maximum of 10 turns. It is shown that HPT leads to grain refinement to a mean equiaxed grain size of similar to 200 nm, the evolution occurs rapidly at the edges of the disks but progresses more slowly in the center of each disk and ultimately, after 10 turns, the grain structure is reasonably homogeneous. There is an evolution also in the grain boundary misorientations and after 5 or more revolutions the fraction of high-angle grain boundaries is about 68%. The texture after HPT is characterized by typical shear components of face-centered cubic metals and mainly by the reinforcement of the {111}< 2 (1) over bar(1) over bar > orientation of the A* texture component. (C) 2013 Elsevier B.V. All rights reserved.The authors wish to thank Mr. Hacen Hadj Larbi from CLA-LFRANCE for kindly providing the CuNiSi alloy and Profs P. Zieba and L. Litynska-Dobrzynska from IMIM-PAN, Cracow, Poland, for their help and assistance with the TEM. This work was supported in part by the National Science Foundation of the United States under Grant No. DMR-0855009, in part by the European Research Council under ERC Grant Agreement No. 267464-SPDMETALS and in part by the Tassili program No. 12MDU862/EGIDE: 26481WM