130
M. Scott and M. Moats
Fig. 1 SEM images of zinc coating surfaces produced in a 267 mL Hull cell with 2 amps of direct
current. Images correspond to a current density of 170 A/m 2 . Synthetic solution conditions: 37.5 g/L
Zn, 210 g/L NaOH and—a No additives, b 1.5 mL/L carrier, c 0.65 mL/L booster, d 1.3 mL/L leveler,
e 1.5 mL/L carrier + 0.65 mL/L booster, f 1.5 mL/L carrier + 1.3 mL/L leveler, g 0.65 mL/L booster
+ 1.3 mL/L leveler, h 0.75 mL/L carrier + 0.33 mL/L booster + 0.65 mL/L leveler
Surface morphologies correlated with the expected structures indicated from the
XRD data. The addition of carrier changed the morphology from hexagonal platelets
to compact grains with a knobby surface. Adding booster with carrier appears to
refine this structure. Finally, adding all three additives can produce a fairly smooth
compact structure.
Despite studying various combinations of additives, no mirror-like deposits were
observed as seen in industrial practice. This is believed to be caused by not properly
aging prior to plating. Even so, the white deposits formed in the same current density
regions as the mirror-like deposits in industrial practice, allowing for electrolyte
comparison.
M. Scott and M. Moats
Fig. 1 SEM images of zinc coating surfaces produced in a 267 mL Hull cell with 2 amps of direct
current. Images correspond to a current density of 170 A/m 2 . Synthetic solution conditions: 37.5 g/L
Zn, 210 g/L NaOH and—a No additives, b 1.5 mL/L carrier, c 0.65 mL/L booster, d 1.3 mL/L leveler,
e 1.5 mL/L carrier + 0.65 mL/L booster, f 1.5 mL/L carrier + 1.3 mL/L leveler, g 0.65 mL/L booster
+ 1.3 mL/L leveler, h 0.75 mL/L carrier + 0.33 mL/L booster + 0.65 mL/L leveler
Surface morphologies correlated with the expected structures indicated from the
XRD data. The addition of carrier changed the morphology from hexagonal platelets
to compact grains with a knobby surface. Adding booster with carrier appears to
refine this structure. Finally, adding all three additives can produce a fairly smooth
compact structure.
Despite studying various combinations of additives, no mirror-like deposits were
observed as seen in industrial practice. This is believed to be caused by not properly
aging prior to plating. Even so, the white deposits formed in the same current density
regions as the mirror-like deposits in industrial practice, allowing for electrolyte
comparison.