Effects of Foreign Ions on Internal Stress of Iron Electrodeposited from Sulfamate Baths (Part 2)

Electrodeposition of Iron from Sulfamic Acid Baths (Part 5)

Abstract

Samples were selected out of metallic ions, anions, and organic compounds having one of the following five properties and their effects on the internal stress were investigated.
(a) Corresponding to compounds, commonly added to the plating bath for buffer action of pH in operation.
(b) Corresponding to compounds, acting as reducing agents to prevent oxidation of ferrous ion.
(c) Corresponding to compounds, producing complexes with ferrous ion.
(d) Corresponding to compounds, indicating possibility of codeposition with iron.
(e) Corresponding to impurities introduced during the employment of mild steel as an anode.
The results obtained were summarized as follows:
1) Cobalt linearly increased the internal stress at a rapid rate. The stress was rapidly increased with the increase in Ni²⁺ concentration and decrease in Fe²⁺ concentration.
2) The internal stress was decreased with the increase in concentration of urea or E. D. T. A.
3) The stress value was lower with the rise of temperature. The value was also lower with the increase in Fe²⁺ concentration at a definite temperature.
4) The stress value was higher with the increase in NH₄HF₂ concentration in the concentration range of 2-20g/l. Addition of a very small amount of saccharin rapidly decreased the stress.