セリウムミッシュメタル-銅-コバルト3元系合金の磁気特性におよぼす高温加熱処理効果について

抄録

Studies on magnetic properties of intermetallic compounds of 3d-transition elements and metals of the rare-earth (R) have been carried out by many workers. Especially, RCo₅ of these compounds have been investigated as a new fine particle permanent magnet, in view of its large magnetocrystalline anisotropy. Recently cast magnets of the RCo₅-RCu₅ system become a subject of ever increasing attention. The present experiment has been carried out to investigate the effect of composition and heat-treatment on magnetic properties of cast (Ce-MM)-Cu-Co ternary alloys. The specimens are made by melting the above ternary alloys with the induction furnace filled with argon gas, and then, cast into the metal or shell mould. These cast samples are heat-treated in the temperature range from 200° to 1220°C.
The results are summarized in the following: (1) In the ternary alloys of (Ce-MM)Cu_xCo_4−x, (Ce-MM)Cu_xCo_4.5−x, and (Ce-MM)Cu_xCo_5−x, the best magnetic properties are obtained in the composition range from x=0.6 to x=1.0. (2) The magnetic properties of these alloys be improved remarkably by the heat-treatment at higher temperature such as 1180°C. (3) The magnetic properties of a typical sample are as follows: 4πI₁₀₀₀₀=5650(G), 4πI_r=5450(G), _IH_C=2450(Oe), _BH_C=1950(Oe), (B·H)_max=3.7(MG·Oe).