Author(s)

A. M. Saliba-Silva, M. A. Baker, H. G. de Me10 & I. Costa

Abstract

Corrosion protection of sintered NdFeB magnets by phosphating A. M. Saliba-SiW, M. A. Baker\ H.G. de Melo^ & I. Costa' * Institute de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Brasil. ^ School of Mechanical and Materials Engineering, University of Surrey, Guildford. * EPUSP - Departamento de Engenharia Quimica, SP, Brasil. Abstract Phosphating of sintered NdFeB magnets has been studied by immersion in a solution of 0.15 M NaK^PC^ acidified to pH 3.7 under polarization. Cyclic polarization experiments indicated that phosphating could be assisted by polarization, with the current density decreasing as the number of polarization cycles increased. Auger electron spectroscopy (AES) and Energy Dispersive X- ray Analysis (EDX) of magnets exposed to the phosphating treatment confirmed the formation of the phosphate layer over both main phases of the specimen, namely, the magnetic () and the Nd-rich phase. Electrochemical impedance spectroscopy (EIS) measurements per

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