Electrodeposition of Ni and Co in low gravity

Electrodeposition of Ni and Co metals under low gravity conditions was investigated, with emphasis on Ni. Custom designed experimental packages aboard sounding rockets were utilized for this purpose. Four missions were employed each providing 7 min of electrodeposition at similar to 10(-4) g. Several deposition conditions were studied including current density, electrolyte composition, substrate nature and deposition cell configuration. High current deposition, encompassing or exceeding 80 mA cm(-2) produced Ni films in the nanocrystalline size range in a reduced gravity environment. Under the same conditions, Earth-produced deposits were crystalline and discontinuous. The convectionless deposition, achieved in low gravity, produced structural anomalies in Ni under specific conditions. Process efficiency and corrosion behaviour for the surfaces were also different in the two environments. The low gravity environment did not affect the electrochemical factors influencing Co deposition for the limited conditions we were able to study. No structural differences were observed between Co deposits in the two environments.