Fully dense Sm2Fe17Nxpermanent magnets prepared by shock compression

Fully dense Sm2Fe17Nx bulk bodies with porosities less than 5% were prepared by shock compression in a certain low‐pressure region, using the magnetically aligned powder pellets with an initial porosity of 46%–52% and without binder. Below a driving shock pressure (single shock wave using a copper standard capsule) of about 10 GPa, the recovered specimens did not consolidate well, and above about 20 GPa they began to decompose to α‐Fe and Sm nitride. The consolidated state and porosity depended on the driving shock pressure, the thickness and porosity of the starting powder pellet, and the thickness of the impact plate. It was found that the shock consolidated bulk bodies had a Curie temperature of approximately 475 °C, and that the magnetic properties were sensitive to shock pressure, porosity, alignment, etc. The largest values of coercivity and maximum energy product of the recovered bulk specimens prepared in this study were 7.1 kOe and 16.8 MGOe, respectively.