Hybrid thermal stabilization of Zr doped nanocrystalline Cu

The present investigation demonstrates the synthesis of nanocrystalline Cu-0.5 at.% Zr alloy through high energy ball milling at cryogenic temperature and thermal stability of the nanocrystalline structure during annealing up to 800 degrees C. The effect of Zr addition on the evolution of microstructure in the cryomilled and annealed alloy has been studied through X-ray diffraction (XRD), transmission electron microscopy (TEM), andMolecular dynamics (MD) simulation. Microhardness measurement has been performed in order to study the stability in the mechanical property of the alloy at high temperature. Analysis of XRD and TEM results show that at high-temperature Zr leaves Cu matrix and nano-size intermetallicCu(5)Zr particle dispersed throughout the matrix, whereas, MD simulation traced atomic clusters of Zr at the vicinity of grain boundaries. Zr stabilizes the average grain size in nano-scale regime even after 800 degrees C due to intermetallic pinning and solute segregation, with very little compromise in the hardness value of only similar to 7.4% (2.9 GPa to 2.4 GPa) compared to the as-milled alloy. (C) 2018 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license