The effect of absorbed hydrogen on the corrosion behavior of NdFeB alloys

The effect of hydrogen on the corrosion behavior of sintered NdFeB alloyed with different elements (Co-V and Nb) is compared using electrochemical galvanostatic and potentiodynamic polarization measurements in 6M KOH. Experimental results show that cathodic currents inject or 'charge' hydrogen into the NdFeB lattice, which can then be oxidized or 'discharged' by the application of anodic currents. Corrosion resistance can be quantified in terms of exchange currents which are shown to be a function of hydrogen content and selection of alloying elements.