OPTIMIZATION OF 2 17 PERMANENT-MAGNETS USING THE QUINARY SM-CO-CU-FE-ZR PHASE-DIAGRAM/

The combination of high magnetisation and high Curie temperature of th e Sm2Co17 type magnets makes them attractive for a number of applicati ons requiring high-energy products and long term stability for continu ous operating up to 300 degrees C. In order to optimise the elaboratio n process, it was necessary to investigate phase equilibria in the Sm- Co-Zr-Cu-Fe system. The presented part of the work concerns two region s of interest near 1150 degrees C and 850 degrees C. A specific method is proposed to represent the diagram where a two dimension projection of the different domains is coupled with a three dimensional one. Thi s representation appears as a tool to understand the metallurgical pro cess and to obtain better reproducibility of the alloys magnetic prope rties. Then an optimisation could be made. Magnetic behaviour of alloy s is discussed. (C) 1998 Elsevier Science S.A.