Didymium-Fe-B sintered permanent magnets

Abstract

Present works describe the developments the low cost R-Fe-B sintered permanent magnets. Three different didymiums are chosen for the low cost mixtures of rare-earth elements. The studied alloy compositions are Fe-(32.5–34.5)wt. %R-(1–1.6)wt. %B, where R elements are didymium (Nd-10wt. %Pr), 5Ce-didymium (Nd-15%Pr-5%Ce), and 40 Ce-didymium (Nd-10%Pr-40%Ce). The specimens were prepared by the conventional powder metallurgical techniques. The best magnetic properties obtained in this studies are Br=13.2 kG, iHc=10.2 kOe, and (BH)max=40 MGOe with the Fe-33.5% (5Ce-didymium)-1%B alloy. Temperature dependence of iHc of this alloy is almost comparable to that of the Nd-Fe-B alloys.