Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

In recent research concerning zinc dissolution studies in boric acid
electrolytes, it was shown that moderate variations of the fluid temperatures
or the boric acid concentration only cause small changes (<10%) in resulting
initial zinc corrosion rates. A stronger dependency was found, however, on the
fluid flow. Thus, a series of electrochemical measurements were carried out
using a rotating disc electrode (zinc) in boric acid electrolytes for a better
understanding of influencing parameters on the zinc corrosion rates. The main
results of these electrochemical polarization experiments (e.g., Tafel plots)
showed similar dependencies of the zinc corrosion rates as described in the
aforementioned zinc dissolution experiments. The zinc corrosion process
strongly depends on the mass transfer limitation of the dissolved oxygen to the
zinc surface (cathodic process). Increased rotation speeds (higher flow rates)
lead to extensively enhanced current densities (corrosion rates) and the
extrapolation to infinite high rotation speeds (Levich extrapolation) was used
to describe the corresponding corrosion process without transfer limitations.