The microstructure and magnetic characteristics of Sm(CobalFe0.1Cu0.09Zr0.03)7.24 high temperature permanent magnets

Abstract Two kinds of Sm(Co bal Fe 0.1 Cu 0.09 Zr 0.03 ) 7.24 high temperature magnets were fabricated by a traditional powder metallurgical technology with different annealing processes. A record of maximum energy product of 94.73 kJ/m 3 at 773 K with a high intrinsic coercivity of 652.72 kA/m was made. Based on the theoretical and experimental results, it was found that the temperature coefficient of the coercivity was strongly influenced by the variation of the Curie temperature of the cell wall phases and the domain wall energy ratio between cell and cell wall phases at 0 K. The characteristic properties originate from the element redistribution between SmCo 5 /Sm 2 Co 17 interfaces while annealing.

[1]  D. Dimitrov,et al.  Microstructure and high temperature magnetic properties of Sm(Co, Cu, Fe, Zr)z (z=6.7–9.1) permanent magnets , 1999 .

[2]  Christina H. Chen,et al.  New sintered high temperature Sm-Co based permanent magnet materials , 1999 .

[3]  Sun Tian‐duo.  A model on the coercivity of the hardened 2–17 rare earth‐cobalt permanent magnets , 1981 .

[4]  Dagmar Goll,et al.  Micromagnetic theory of the pinning of domain walls at phase boundaries , 2002 .

[5]  D. Goll,et al.  Micromagnetic analysis of pinning-hardened nanostructured, nanocrystalline Sm2Co17 based alloys , 2002 .

[6]  Toshiyuki Koyama,et al.  The microstructure of sintered Sm (Co0.72Fe0.20Cu0.055Zr0.025) (7.5) permanent magnet studied by atom probe , 2004 .

[7]  D. Goll,et al.  Analysis of the temperature dependence of the coercive field of Sm2Co17 based magnets , 2003 .

[8]  G. Hadjipanayis,et al.  New rare-earth permanent magnets with an intrinsic coercivity of 10 kOe at 500 °C , 1999 .

[9]  G. Hadjipanayis,et al.  Effect of iron on the high temperature magnetic properties and microstructure of Sm(Co, Fe, Cu, Zr)z permanent magnets , 1999 .

[10]  E. Lectard,et al.  Saturation magnetization and anisotropy fields in the Sm(Co1−xCux)5 phases , 1994 .

[11]  Y. Fang,et al.  Magnetic microstructures of phase-separated Sm–Co 2:17-type sintered magnets , 2008 .

[12]  Thomas Schrefl,et al.  Correlation of microchemistry of cell boundary phase and interface structure to the coercivity of Sm(Co0.784Fe0.100Cu0.088Zr0.028)7.19 sintered magnets , 2017 .

[13]  R. Gopalan,et al.  Direct evidence for Cu concentration variation and its correlation to coercivity in Sm(Co0.74Fe0.1Cu0.12Zr.04)7.4 ribbons , 2009 .

[14]  D. Nishio–Hamane,et al.  Magnetic properties of SmCo5−xFex (x = 0–4) melt-spun ribbon , 2014 .

[15]  Wei Sun,et al.  Magnetic properties and microstructures of high-performance Sm2Co17 based alloy , 2015 .

[16]  Wei Sun,et al.  The coercivity mechanism of sintered SM(CobalFe0.245Cu0.07Zr0.02)7.8 permanent magnets with different isothermal annealing time , 2015 .

[17]  Tianli Zhang,et al.  2:17-type SmCo quasi-single-crystal high temperature magnets , 2015 .

[18]  L. Schultz,et al.  Evolution of magnetic domain structures and coercivity in high-performance SmCo 2:17-type permanent magnets , 2006 .