Enhanced corrosion resistance of sintered NdFeB magnets by diffusion of Co film prepared by direct current magnetron sputtering deposition

摘要

In this study, the Co films were prepared by direct current (DC) magnetron sputtering deposition onto the substrates of sintered NdFeB magnets (N46) which were made by conventional powder metallurgy route. Magnetic properties, grain boundary and corrosion resistance were observed for the heat treated magnets. Highly accelerated stress test, energy-dispersive X-ray spectroscopy, SEM, TEM and electron back-scattering pattern method were employed to study the surface morphology and grain boundary phase modification by Co diffusion on the surface of the magnets.