Pulse Plating Of Ni-nd-p Alloy Thin Films Of Rare Earth

Thin films of rare earths have been applied widely in magnetic, optical, electrolytic and superconductor devices, and aroused many material researchers' interests.In this paper, the properties and application of rare earth are summarized. Theory for pulse electrodeposition of rare earth metals and their alloys from aqueous solution are discussed, which has more advantages than using direct current.The gray films with a thickness up to 5μm of Ni-Nd-P alloys was successfully prepared on copper substrate by pulse electrodeposition from aqueous bath. The effects of pulse current, pulse frequency and duty ratio on deposition rate, morphologies, mechanical properties and corrosion resistance are studied.Proper technological parameters were obtained for the realization of the codeposition of Ni-Nd-P alloys with fine quality. The appearance of alloy films was analyzed by scanning electron microscopy(SEM).The result shows that the surface of alloy films is smoother and crystals are closer than using direct current. In addition, the effects of heat treatment temperature on the microhardness of alloy deposits were studied in this paper. The results of the microhardness of films show that the rare earth alloy films have higher hardness than Cu substrate material.The films deposited by pulse current are better than those by direct current in hardness. After heart treating from 300℃ to 600℃, hardness of rare earth alloy films decreases with the increase of annealing temperature.Aiming at the difficulties of electrodepositing rare earth alloys from aqueous solution, the effect of the complex formation (formed with Cit and NH4CI) on the reductive potential of RE and nickle was studied by the way of electrochemistry. The potencial of RE shifted positively which made itself electrodeposited from aquous solution possibly and nickle negatively which may make it into realities codepositing the two metals whose reductive potentials has far distance.