Effect of Mn on Hydrogenation Behavior of Sm(Co bal. Fe 0.2 Mn x Cu 0.08 Zr 0.025 ) 7.2 Alloys

The effect of Mn on hydrogenation behavior and magnetic properties of 2:17 type SmCo alloys was investigated. The as-cast Sm(Co bal. Fe 0.2 Mn x Cu 0.08 Zr 0.025 ) 7.2 alloys with $x = 0$ , 0.04, 0.08, and 0.12 were all decrepitated under hydrogen pressure of 0.3 MPa at room temperature. The hydrogenation ability of as-cast alloys was obviously improved with the increase of Mn content. The size of particles was decreased with the increase of Mn content due to the network structure diminishing with Mn content increasing. The phase and microstructure changes of as-cast alloys were discussed. Research results show that Mn-doped has a great effect on the grain boundary phase, which lead to the high hydrogen absorption ability and the broken of as-cast alloys. The following magnetic properties were obtained for Sm(Co bal. Fe 0.2 Cu 0.08 Mn 0.04 Zr 0.025 ) 7.2 magnet: $B_{r} = 10.6$ kGs, $H_{\text {cj}} = 28.35$ kOe, and $(BH)_{\mathrm {\mathbf {max}}} = 26.74$ MGOe.