Nanostructured Melt-Spun Sm(Co,Fe,Zr,B)7:5 Alloys for High-Temperature Magnets

TL;DR

This study develops nanostructured melt-spun Sm(Co,Fe,Zr,B)7.5 alloys with high coercivity and thermal stability, suitable for high-temperature magnets, demonstrating superior magnetic properties and structural characteristics.

Contribution

It introduces a new class of nanostructured Sm-Co-based alloys with enhanced coercivity and thermal stability for high-temperature magnetic applications.

Findings

Achieved coercivity up to 232 kOe in as-spun samples.

Maintained high coercivity (>5 kOe) at 330°C.

Obtained high energy product of 10.7 MGOe in annealed samples.

Abstract

High coercivity, the highest for Cu-free 2 : 17 Sm-Co ribbons, has been obtained in as-spun (= 211 kOe) and short time annealed (= 232 kOe) samples of Sm(CobalFe Zr B)7 5 alloys, with varying B, Zr, and Fe content (= 0-0 06, = 0-0 16, = 0 08-0 3) and wheel speed. In as-spun samples, the TbCu7 type structure and in annealed samples the Th2Zn17 and CaCu5 type structures is observed, plus fcc Co as minority phase is observed. Reduced remanence () is higher than 0.7. High-temperature magnetic measurements show very good stability above 300 C with coercive field as high as 5.2 kOe at 330 C. For annealed Sm(CobalFe0 3Zr0 02B0 04)7 5, very good loop squareness and high maximum energy product of 10.7 MGOe have been obtained. Increasing Zr content results in less uniform microstructure of annealed ribbons.