Improvements of the magnetic properties of equiaxed Fe-Cr-Co-Mo hard magnets by two-step thermomagnetic treatment

Present works describe the developments of the equiaxed Fe-Cr-Co permanent magnets with high coercivity and high energy products. The studied alloy compositions are Fe-(26-32)wt%Cr-15wt%Co-3wt%Mo. The magnetic properties of the alloys have been enhanced by the two-step thermomagnetic treatment (two-step TMT) and by prolonging all of the heat-treatment time. The energy products above 43 kJm^-3(5.4MGOe) are obtained for almost all of the studied compositional alloys. Fe- 30%Cr-15%Co-3%Mo alloy gives good magnetic properties as iHc=76.8 kAm^-1(960 Oe), (BH)max=49.6 kJm^-3(6.2 MGOe). The highest coercivity achieved with Fe-32%Cr- 15%Co-3%Mo alloy is 80.8 kAm^-1(1010 Oe).