Structure and Magnetic Properties of (Pr,Dy)–(Fe,Co)–B Alloys Prepared by Rapid and Slow Melt Cooling

The structure of the (Pr 1 – x Dy x ) 13.4 (Fe 1 – y Co y ) 79.1 B 7.5 and (Pr 1 – x Dy x ) 12.7 (Fe 1 – y Co y ) 87.2 B 10.1 alloys in the as-cast state after conventional solidification and after rapid quenching by melt spinning is studied. Phase analysis shows that, in the case of alloys with a higher boron content, the content of weakly magnetic phases increases. Differential scanning calorimetry allowed us to identify the magnetocaloric effect in the usually cast alloys at their Curie temperature and the crystallization and recrystallization processes of amorphous phase in the rapidly quenched alloys. The alloys in the initial cast state are characterized by a low coercive force of 0.8–8 kA/m (10–100 Oe). The rapidly quenched alloys, in which 2-14-1 main magnetic phase inclusions (REM 2 (Fe, Co) 14 B) are small (~10 μm) and well isolated from each other by an amorphous phase, are characterized by a high coercive force of 1600 kA/m (20 kOe).