Role of Mo addition on structure and magnetic properties of the Fe85Si2B8P4Cu1 nanocrystalline alloy

Abstract The amorphous-forming ability (AFA), crystallization structure and magnetic properties of the melt-spun Fe85 − xSi2B8P4Cu1Mox (x = 0–2) alloys were investigated. The addition of 1–2 at% Mo in the Fe85Si2B8P4Cu1 alloy enhances the AFA with increasing the critical thickness for amorphous formation from ~ 14 to ~ 20 μm. The Mo alloying refines the microstructure and reduces the coercivity of the annealed alloys, and weakens the dependence of the coercivity on the heating rate, although it decreases the saturation magnetic flux density. After annealing under a low heating rate of 50 K/min, the average α-Fe grain size and coercivity of the Fe84Si2B8P4Cu1Mo1 alloy are ~ 25 nm and 23.9 A/m, respectively, which are lower than those of ~ 32 nm and 40.5 A/m for the base alloy. In addition, the mechanism related to the effects of Mo on the structure and magnetic properties was discussed in term of the crystallization activation energy.

[1]  Wei Zhang,et al.  Ferromagnetic Fe-based bulk metallic glasses with high thermoplastic formability , 2013 .

[2]  Chun-tao Chang,et al.  Optimization of thermal stability and soft-magnetic properties of FeSiBPCuNb alloys by Nb content tuning , 2015 .

[3]  Akira Takeuchi,et al.  Classification of Bulk Metallic Glasses by Atomic Size Difference, Heat of Mixing and Period of Constituent Elements and Its Application to Characterization of the Main Alloying Element , 2005 .

[4]  H. E. Kissinger.  Reaction Kinetics in Differential Thermal Analysis , 1957 .

[5]  M. McHenry,et al.  Structure and magnetic properties of (Fe0.5Co0.5)88Zr7B4Cu1 nanocrystalline alloys , 1998 .

[6]  Akihiro Makino,et al.  High Saturation Magnetization and Soft Magnetic Properties of bcc Fe–Zr–B Alloys with Ultrafine Grain Structure , 1990 .

[7]  M. Avrami.  Kinetics of Phase Change. II Transformation‐Time Relations for Random Distribution of Nuclei , 1940 .

[8]  Akihiro Makino,et al.  Low core losses of nanocrystalline Fe-M-B (M=Zr, Hf, or Nb) alloys , 1993 .

[9]  Y. Yoshizawa,et al.  New Fe-based soft magnetic alloys composed of ultrafine grain structure , 1988 .

[10]  G. Herzer,et al.  Grain size dependence of coercivity and permeability in nanocrystalline ferromagnets , 1990, International Conference on Magnetics.

[11]  M. Avrami.  Granulation, Phase Change, and Microstructure Kinetics of Phase Change. III , 1941 .

[12]  Wei Zhang,et al.  Effects of Mo addition on thermal stability and magnetic properties of a ferromagnetic Fe75P10C10B5 metallic glass , 2014 .

[13]  Weihua Wang.  Roles of minor additions in formation and properties of bulk metallic glasses , 2007 .

[14]  Shigeyoshi Yoshida,et al.  Low core losses and magnetic properties of Fe85-86Si1-2B8P4Cu1 nanocrystalline alloys with high B for power applications (invited) , 2011 .

[15]  Akihiro Makino,et al.  Nanocrystalline Soft Magnetic Fe-Si-B-P-Cu Alloys With High $B$ of 1.8–1.9T Contributable to Energy Saving , 2012, IEEE Transactions on Magnetics.

[16]  W. Johnson,et al.  Formation of Ti–Zr–Cu–Ni bulk metallic glasses , 1995 .

[17]  A. Inoue.  Stabilization of metallic supercooled liquid and bulk amorphous alloys , 2000 .

[18]  X. M. Zhang,et al.  Competition driven nanocrystallization in high Bs and low coreloss Fe–Si–B–P–Cu soft magnetic alloys , 2015 .

[19]  A. Inoue,et al.  Structure and Magnetic Properties of Fe42.5Co42.5Nb7B8 Nanocrystalline Alloy , 2002 .

[20]  M. McHenry,et al.  Magnetic properties of HITPERM (Fe, Co)88Zr7B4Cu1 magnets , 1999 .

[21]  P. Ramachandrarao,et al.  The kinetics of crystallisation of an FePC glass , 1977 .

[22]  M. Avrami.  Kinetics of Phase Change. I General Theory , 1939 .