Optimizing Additive Ratios in Alkaline
Zincate Electrodeposition
Margaret Scott and Michael Moats
Abstract Alkaline non-cyanide zinc electrogalvanizing is utilized in some plating
applications. This study was conducted to evaluate the effects of a commercial carrier,
booster, and leveler in a strong zinc (37.5 g/L) and alkaline (210 g/L) plating solution.
Hull cell plating was used to assess the roles of each additive on the appearance of
the zinc deposits produced from synthetic solutions. Bright white deposits were
generated with several different combinations of additives at current densities of
170–420 A/m
2 . The zinc structures were characterized using x-ray diffraction and
scanning electron microscopy to understand the microstructure which produced the
bright deposits in order to determine the optimal conditions leading to mirror-like
deposits.
Keywords Zinc · Electrogalvanizing · Alkaline · Zincate · Non-cyanide ·
Additives · Hull cell
Introduction
Steel is the world’s most widely used metal. Unfortunately, steel is highly susceptible
to rust, leading to many steel pieces to be coated to prevent corrosion. Galvanizing
with zinc is a common method to cover the steel substrate and provide a sacrificial
protective layer. Galvanization can be achieved through hot dipping or electroplating.
Hot-dip galvanizing has been and continues to be the primary coating method. In
a few applications, electrogalvanizing is the preferred method of applying zinc to
steel.
In the early 1900s, several industries moved away from hot-dip galvanizing for
electrogalvanizing, in favor of a thinner and more controlled coating [1]. Over time,
zinc electrogalvanizing baths used cyanide as a means to complex the zinc in solution
and form a stable zinc coating bath. Zinc cyanide plating baths produce excellent
M. Scott · M. Moats (B)
Materials Research Center, Missouri University of Science and Technology,
Rolla, MO 65409, USA
e-mail: moatsm@mst.edu
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_11
123
Zincate Electrodeposition
Margaret Scott and Michael Moats
Abstract Alkaline non-cyanide zinc electrogalvanizing is utilized in some plating
applications. This study was conducted to evaluate the effects of a commercial carrier,
booster, and leveler in a strong zinc (37.5 g/L) and alkaline (210 g/L) plating solution.
Hull cell plating was used to assess the roles of each additive on the appearance of
the zinc deposits produced from synthetic solutions. Bright white deposits were
generated with several different combinations of additives at current densities of
170–420 A/m
2 . The zinc structures were characterized using x-ray diffraction and
scanning electron microscopy to understand the microstructure which produced the
bright deposits in order to determine the optimal conditions leading to mirror-like
deposits.
Keywords Zinc · Electrogalvanizing · Alkaline · Zincate · Non-cyanide ·
Additives · Hull cell
Introduction
Steel is the world’s most widely used metal. Unfortunately, steel is highly susceptible
to rust, leading to many steel pieces to be coated to prevent corrosion. Galvanizing
with zinc is a common method to cover the steel substrate and provide a sacrificial
protective layer. Galvanization can be achieved through hot dipping or electroplating.
Hot-dip galvanizing has been and continues to be the primary coating method. In
a few applications, electrogalvanizing is the preferred method of applying zinc to
steel.
In the early 1900s, several industries moved away from hot-dip galvanizing for
electrogalvanizing, in favor of a thinner and more controlled coating [1]. Over time,
zinc electrogalvanizing baths used cyanide as a means to complex the zinc in solution
and form a stable zinc coating bath. Zinc cyanide plating baths produce excellent
M. Scott · M. Moats (B)
Materials Research Center, Missouri University of Science and Technology,
Rolla, MO 65409, USA
e-mail: moatsm@mst.edu
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_11
123