Dy Electrodeposition on Sintered Nd-Fe-B

A low-cost, high-efficiency electrodeposition technique was used to enhance the coercivity of Nd-Fe-B. Dy was electrodeposited on the surface of a sintered Nd-Fe-B magnet in a nonaqueous solution. The use of the organic solvent dimethylformamide results in improved electrodeposition and adhesion compared to ethanol. A dense deposition layer was achieved when current density was < 8 A/dm(2). A 20 mu m layer of Dy increased the Nd-Fe-B coercivity from 1032 kA/m to 1532 kA/m while maintaining high squareness, without a marked decrease in remanence.