High thermal stability and corrosion resistance of SmCo based magnets surface modified by Ni coating

High temperature resistance improvement (500 °C) and corrosion resistance in salt spray test (47 °C) at different time intervals with and without surface modified with Ni coating of SmCo alloy was carried out. The results showed that mass gain of Ni coated sample is far less then uncoated sample when oxidized at 500 °C for 300h and the loss of magnetic properties for coated magnets were also almost unnoticeable as compare to uncoated magnets. The x-ray diffraction (XRD) and electron probe microanalysis (EPMA) results also supported the fact that a surface modified magnet with Ni has better performance at high temperature. Also in corrosive environment Ni coated magnet showed better results than uncoated magnet.