Corrosion characteristics of Nd/sub 2/Fe/sub 14-x/Ni/sub x/B permanent magnets

The influence of nickel additions in Nd/sub 2/Fe/sub 14-x/Ni/sub x/B (x=0, 5, 7, 10, 14) magnets on the kinetics and mechanism of electrochemical corrosion in 0.5 M H/sub 2/SO/sub 4/ and Na/sub 2/SO/sub 4/ solutions was determined on the basis of potentiokinetic polarization curves and corrosion rates in the passive and strong cathodic range. It is shown that the replacement of part of the iron with nickel causes a strong decrease in the acid corrosion rate of the alloys tested, whereas the additions of nickel degrade the behavior of the alloy in the passive range and make it easier to hydrogenate the alloy at strong cathodic polarizations, leading to mechanical degradation of the alloy surface as well.<
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