Hydrogen embrittlement failure of (Sm,Dy,Gd)Co5 permanent magnets

Abstract The effect of long-term hydrogenation of the (Sm,Dy,Gd)Co 5 permanent magnet on mechanical degradation and decay of magnetic properties in service is investigated. The application of ⩾15 μ m Cd-coatings is recommended to prevent the hydrogenation of the permanent magnet.