An X-ray absorption spectroscopy investigation of the local atomic structure in Cu–Ni–Si alloy after severe plastic deformation and ageing

Abstract

The local atomic structure of Cu–Ni–Si alloy after severe plastic deformation (SPD) processing and the decomposition of supersaturated solid solution upon annealing were investigated by means of X-ray absorption spectroscopy. The coordination number and interatomic distances were obtained by analyzing experimental extend X-ray absorption fine structure data collected at the Ni K-edge. Results indicate that the environment of Ni atoms in Cu–Ni–Si alloy is strongly influenced by the deformation process. Moreover, ageing at 973 K affects strongly the atomic structure around the Ni atoms in Cu–Ni–Si deformed by equal channel angular pressing and high pressure torsion. This influence is discussed in terms of changes and decomposition features of the Cu–Ni–Si solid solution.

Keywords:

• Cu–Ni–Si alloy
• severe plastic deformation
• equal channel angular pressing
• high-pressure torsion
• precipitation
• synchrotron X-ray diffraction

Acknowledgements

One of the authors (D. Bradai) heartily acknowledges the support of SOLEIL synchrotron facility while performing the experiments through the 20120314 proposal.