Influences of process parameters on the composition of an electrodeposited invar alloy coating

A Fe-Ni alloy coating was prepared in a sulfate bath by electrodeposition. The influences of process parameters, such as Fe²⁺/Ni²⁺ molar ratio, CeCl₃ concentration, ascorbic acid concentration, bath temperature, pH, cathodic current density and deposition time, on the ferrous content in the coating were studied. An optimum process condition was determined for the electrodeposition of invar alloy. The coating obtained under the optimum condition was analyzed by EDS, XRD and TEM. The results showed that the mass fractions of Fe and Ni in the coating were 61.8%-62.1% and 37.9%-38.1%, respectively, similar to those of invar alloy, and the coating was solely composed of nanocrystalline γ solid solution.