By means of pulse electrodeposition technique, a nanocrystalline Cu-0.42at.%Bi alloy with a grain size down to ~10 nm was synthesized. The thermal stability of Cu-Bi electrodeposit was investigated using differential scanning calorimetry (DSC), x-ray diffraction (XRD), transmission electron microscopy (TEM), and hardness measurements. The temperature at which this material tends to become unstable was found to be 160 °C. DSC revealed an exothermal peak between 190 and 300 °C, caused by grain growth. It was observed that segregation of Bi at grain boundary has a considerable effect on the thermal stability of the Cu-Bi alloy. Tensile test showed the sample interestingly possesses a high strength of 760 MPa, while no plastic strain is detected.
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