Annealing behaviour of a nanostructured Cu–45 at.%Ni alloy
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The microstructure and crystallographic texture have been investigated in a Cu–45 at.%Ni alloy after heavy rolling and subsequent annealing at different temperatures. Cold-rolling to a von Mises strain of 5.7 produced a sample with an average boundary spacing along the normal direction of ~70 nm and a large fraction of high-angle boundaries (HABs), ~70 %. Annealing of this sample for 1 h at temperatures ≤450 °C causes structural coarsening, during which the fraction of HABs decreases. Annealing at higher temperatures results in pronounced discontinuous recrystallization accompanied by twinning. Large frequencies of twin boundaries contribute to high HAB fractions measured in the as-recrystallized condition. Cube-oriented grains demonstrate a size advantage compared to grains of other orientations, thus creating a strong cube texture in the recrystallized material. Further annealing of the recrystallized microstructure promotes grain growth, which leads to a significant strengthening of the cube texture and to a dramatic loss of HABs. After 1 h of annealing at 1000 °C the fraction of the cube texture reaches 99 % and the HAB fraction is 12 %.
KeywordsShear Band Critical Current Density Rolling Plane Cube Texture Strong Cube Texture
The authors gratefully acknowledge the support from the Danish National Research Foundation (Grant No. DNRF86-5) and the National Natural Science Foundation of China (Grant No. 51261130091) to the Danish-Chinese Center for Nanometals, within which part of the present work was performed. H.T. and H.L.S. are also grateful to the National Natural Science Foundation of China (51171002), Beijing Municipal Natural Science Foundation (2132011 and KZ201310005003), the Specialized Research Fund for the Doctoral Program of Higher Education (20121103110012) and the Danish Agency for Science, Technology and Innovation (Grant No. 09-065234) for supporting this research work. Professor A. Godfrey is acknowledged for useful comments on the manuscript.
- 8.Tian H, Zhang YB, Mishin OV, Suo HL, Grivel J-C (2012) In: Proceedings of 33rd Risø international symposium on materials science, Roskilde: 349–354Google Scholar