Evaluation of Practicality for Fully Dense Isotropic Sm-Fe-N Magnets Made by Shock-Wave Consolidation Method

Fully dense isotropic Sm-Fe-N magnets were successfully fabricated using the shock-wave consolidation method. Deterioration of hard magnetic properties of the Sm-Fe-N by the impact load during the consolidation process was not observed, and consequently, the fully dense magnet showed high (BH)max of 116–144 kJ/m3 (14.5–18.0 MGOe) which is the highest level among all the isotropic magnets. Its temperature coefficient of
$B_{\mathrm {r}}$
was 0.066%/°C and that of coercivity was 0.36%/°C. The irreversible flux loss of the sample with
$L/D$
of 0.78 after exposed at 150 °C was a small value of 5%–10%. The fully dense Sm-Fe-N magnet without coating showed a good corrosion resistance, and it had enough mechanical strength. The volume resistivity of the consolidated Sm-Fe-N magnet with a packing ratio of 97.4% was
$2.8 ~\mu \Omega \cdot \text{m}$
. From these results, the practicality of the fully dense Sm-Fe-N magnet made by shock-wave consolidation has been confirmed.