Effect of degree of die upset on magnetic behavior in Nd13.9(Fe0.92Co0.08)80.3B5.3Ga0.5

DC demagnetization (DCD), isothermal remanent magnetization (IRM), and reversible magnetization measurements were used to examine the magnetic reversal behavior in melt-quenched samples of composition Nd13.9(Fe0.92Co0.08)80.3B5.3Ga0.5 subjected to different levels of thermomechanical deformation (die upsetting). The reversible magnetization measurements indicate that in the thermally demagnetized condition domain walls are present within the material for all levels of deformation. During demagnetization from a saturated state, domain walls are present in a minority of grains at low levels of deformation but these domain walls disappear at higher levels of deformation. This behavior is explained in terms of changes in the relative strengths of nucleation and pinning fields. Comparison of these results to previous results obtained on similar materials indicate that changes in the magnetization behavior with degree of deformation are more marked in samples which are free of Ga, indicating that Ga additions a...

[1]  R. Street,et al.  An investigation of reversible magnetization in NdFeB , 1999 .

[2]  L. H. Lewis,et al.  Spatial texture distribution in thermomechanically deformed 2–14–1-based magnets , 1997 .

[3]  M. Leonowicz,et al.  Effect of gallium additions on the magnetic properties of die-upset forged Fe-Nd-B type melt spun alloys , 1995 .

[4]  Yimei Zhu,et al.  Ferromagnetic grain boundary signature in die-upset Re-Fe-B magnets , 1995 .

[5]  L. H. Lewis,et al.  Evidence for reversal by nucleation in RE‐Fe‐B die‐upset magnets , 1994 .

[6]  R. Street,et al.  Investigation of interaction mechanisms in melt‐quenched NdFeB , 1994 .

[7]  R. Mishra,et al.  The microstructure of hot formed neodymium–iron–boron magnets with energy product 48 MG Oe , 1993 .

[8]  F. Pinkerton,et al.  A strong pinning model for the coercivity of die-upset Pr-Fe-B magnets , 1991 .

[9]  H. Kronmüller,et al.  Initial magnetization curve and hardening mechanism in rapidly quenched NdFeB magnets , 1990 .

[10]  D. Givord,et al.  Intrinsic and extrinsic properties of rare earth-transition metal compounds and permanent magnets , 1990 .

[11]  D. Givord,et al.  Angular dependence of coercivity in sintered magnets , 1988 .

[12]  H. Kronmüller,et al.  The coercive field of sintered and melt-spun NdFeB magnets , 1987 .

[13]  R. Mishra.  Microstructure of melt-spun Nd-Fe-B magnequench magnets , 1986 .

[14]  E. Wohlfarth.  Relations between Different Modes of Acquisition of the Remanent Magnetization of Ferromagnetic Particles , 1958 .