Porosity of nickel electrodeposits on mild steel using electrochemical impedance spectroscopy

Abstract

Impedance spectroscopy recorded at the open circuit potential in 1M H₂SO₄ at 293 K is shown to provide a convenient test for detecting the degree of through porosity in electroplated nickel coatings, electrodeposited from a Watts bath, on mild steel. The impedance data can be interpreted in terms of a simple equivalent circuit, and the corrosion resistance provides a reliable guide to the quality of the deposit. The quantitative estimation of porosity from these data is considered.