Abstract
Zn-Ni-P alloys were prepared using electrodeposition in alkaline solutions. The alloys, which had high Zn content ratios and high corrosion resistance, were controlled by varying the applied potential and composition of the plating bath. The respective alloy compositions were analyzed using inductively-coupled plasma atomic emission spectrometry. Compounds were identified using X-ray diffraction analysis. Scanning electron microscopy was used to elucidate the surface morphology. Alloys containing 25.2-82.7 mol% Zn, 17.0-67.5 mol% Ni, and 0.3-11.9 mol% P were obtained by potentiostatic electrolysis of 6 C. The alloy having highest corrosion resistance with performance equivalent to Ni-P alloys contained 58.1 mol% of Zn and 40 mol% of Ni. The alloy was black, with grains of about 0.25 μm diameter. Results from inductively-coupled plasma atomic emission spectrometry analysis showed that the current efficiency of the plating film with high corrosion resistance was 10.5-21.3 %. The film thickness was 1-2 μm. X-ray diffraction analysis of these films revealed no peaks such as those of Ni3P, Ni, Zn and Ni5Zn21 alloys. These films had low crystallinity.
