Title :
Effect of Strip Casting on Microstructure and Magnetic Properties of 2:17 Type Sm-Co Sintered Magnets
Author :
Lei Liu ; Zhuang Liu ; Renjie Chen ; Xingmin Liu ; Aru Yan ; Don Lee ; Wei Li
Author_Institution :
Key Lab. of Magn. Mater. & Devices, Ningbo Inst. of Mater. Technol. & Eng., Ningbo, China
Abstract :
The 2:17 type Sm-Co sintered magnets were made with strips and ingots, separately. The phase structure and microstructure of the cast alloys and their effects on magnetic properties of the magnets have been comparatively studied. X-ray diffraction analysis shows that the phase structure of strips and ingots both consist of TbCu7-type phase with a little CaCu5-type phase. Scanning electron microscopy research shows that the microstructure of strips is composed of dendritic crystal grains which are larger than 10 μm in cross section and less than 4 μm in the free side, whereas, the grain size of ingots is larger than 40 μm. Higher remanence and maximum magnetic energy product are observed in magnets made with ingots (IM) than that made with strips (SM), which is due to low grain alignment degree of the magnets made with strips. In order to increase the grain alignment degree of magnets made with strips, the powder particle size has been reduced. Fruitfully, the remanence and the maximum energy products gradually increase with decreasing the powder particle size.
Keywords :
X-ray diffraction; casting; cobalt alloys; grain size; ingots; magnetic particles; particle size; permanent magnets; powders; remanence; samarium alloys; scanning electron microscopy; sintering; SmCo; X-ray diffraction; dendritic crystal grains; grain alignment degree; grain size; ingots; magnetic properties; maximum magnetic energy; microstructure; phase structure; powder particle size; remanence; scanning electron microscopy; sintered magnets; strip casting; Magnetic properties; Magnetic separation; Metals; Perpendicular magnetic anisotropy; Powders; Strips; 2:17 type Sm-Co; Grain alignment degree; ingots; strip casting;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2013.2276064