Journal of Applied Electrochemistry, Vol.34, No.1, 19-30, 2004
Electromagnetic control of electroplating of a cylinder in forced convection
Continuous electrodeposition on a cylindrical cathode, e. g. electrodeposition of gold on electrical connectors, is usually characterized by an undesirable non- homogeneity of the deposit thickness. This has been observed in industrial applications. Numerical simulations have shown very good agreement with observations. This paper deals with the possibility of improving the homogeneity of the deposit thickness by a magnetic field that is parallel to the axis of the cylinder. The electromagnetic volume force generated by such a magnetic field may set up a swirling motion around the cylinder. By controlling the force density it is possible to control the thickness of the diffusive layer and consequently the mass transfer. The magnetic field can be optimized with respect to strength, spatial extent and variation with time. It is shown that a strong alternating magnetic field of low frequency gives a nearly homogeneous deposit.
Keywords:cylinder;electrochemical coating;electrodeposition;forced convection;magnetic field;magnetoelectrolysis;mass transport;numerical solutions