Abstract
Calcium tripolyphosphate films have been formed on steel electrodes by polarizing them slightly cathodically in a dilute aqueous solution containing Ca (NO3) 2 and Na5P3O10.
When the solutions were adjusted to pH near the point where calcium tripolyphosphate was precipitated, they were supersaturated with calcium tripolyphosphate. Supersaturation was maintained during the film formation. It was found that the electrodeposition rate of calcium tripolyphosphate were determined by the degree of supersaturation and current density.
The degree of supersaturation which depends on the concentration of the reagents, pH and the temperature, influence on the electrodeposition rate to a greater extent than current density. The film thus can be formed from dilute aqueous solutions and at the very low current density.
