State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials,Southwest University of Science and Technology,Mianyang 621010,China
Bismuth plating was obtained on copper substrate by using pulse electroplating in cyanide-free system. The optimal pulse parameters were determined by orthogonal test as follows: current density 5 A/cm2, frequency 600 Hz, duty ratio 1∶6, temperature 20 ℃. Furthermore, scanning electron microscope and scanning probe microscope were used to characterize the morphology of the bismuth plating, and X-ray diffraction was used to analyze the phase components. The bismuth plating has fine and uniform grains, with low porosity, good smoothness and free of cracks.