A Study of the Magnetic and Metallurgical Properties of Sm(Co,Fe,Cu,Zr) z Alloys with z = 8.5.
Final summary rept. 6 Aug 79-5 Aug 80,
DAYTON UNIV OHIO
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This study was aimed at developing a better understanding of the preparation parameters and microstructural features that control magnetic hardness in alloys of the type Sm2Co,Fe,Cu,T17. Here, T is one or more additional transition metal. The basic intermetallic compound Sm2Co17 and its modifications with Fe have very high uniaxial crystal anisotropy, which promises the possibility of good permanent magnets, but ingots, powders, or sintered bodies were found to always have low coercive force. Research workers at the TDK, Hitachi, and other commercial laboratories in Japan reported that by adding small percentages of copper plus one other metal of the group Zr, Hf, Ti, or Mn, and by fairly complicated heat treatments, it is possible to produce usefully high coercive forces in the 5-7 kOe regime. Quite recently, coercivities twice as high were reported by TDK. This report first describes the alloy preparation effort which had to precede any magnetic characterization or magnet preparation work. In the second half, we report on the results of measurements of basic magnetic properties of the alloys, powder preparation, field pressing, and sintering experiments.
- Metallurgy and Metallography
- Fabrication Metallurgy
- Electricity and Magnetism