The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
E. S. Gorkunov - One of the best experts on this subject based on the ideXlab platform.
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A Permanent Magnet Device for Measuring the Coercive Force
2020Co-Authors: E. S. Gorkunov, Vera P. TabachnikAbstract:An attached magnetic device comprising two permanent magnets for magnetizing and demagnetizing is considered. The angular displacement of o ne magnet, with the other being set at a preset angle, is the test parameter proportion al to the Coercive Force of the articles.
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Coercive-Force hysteresis of carbon steels during elastic cyclic tensile deformation
Russian Journal of Nondestructive Testing, 2013Co-Authors: V. A. Zakharov, A. I. Ul’yanov, E. S. Gorkunov, V. V. VelichkoAbstract:Dependences of the Coercive Force and mechanical stresses on cyclic tensile in the region of elastic deformation of steel samples with various carbon contents (Armco iron, 3, 8) are investigated. It is shown that the dependence of the Coercive Force on cyclic elastic tensile deformation is reversible for well-annealed samples. The dependence for plastically deformed steels has a hysteresis loop that is significantly determined by the carbon content and increases with an increasing degree of plastic deformation. It is assumed that the hysteresis of the Coercive Force as a function of elastic cyclic tensile deformations in plastically deformed carbon steels is caused generally by the appearance “free” carbon atoms, i.e., those not bound in carbide phases, which act as interstitial impurity atoms in the lattice of α-iron.
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Coercive Force of ferromagnetic steels under the biaxial symmetrical tension of a material
Russian Journal of Nondestructive Testing, 2011Co-Authors: V. A. Zakharov, A. I. Ul’yanov, E. S. GorkunovAbstract:Patterns of Coercive Force variations of C t .3 and X70 ferromagnetic steels under biaxial symmetrical tension within both elastic and plastic ranges of deformation were studied using X-shaped specimens. It was shown that the Coercive Force of isotropic polycrystalline materials increased during plastic deformation under biaxial symmetrical tension and was proportional to applied stresses (loads). Plastic deformation of materials with high initial Coercive-Force anisotropy along the principal directions (X70 steel) leads to an abrupt decrease in anisotropy and subsequent alternation of its sign. The patterns of a material’s Coercive Force behavior allow the Coercive Force to be used for estimating the stress-strain state (from both an increase in the Coercive Force and its variations during loading as compared to that of the initial material) of articles made from the studied steels under biaxial symmetrical tensile deformation.
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regularities of the change in the Coercive Force under biaxial asymmetric deformation of steel 3
Russian Journal of Nondestructive Testing, 2010Co-Authors: V. A. Zakharov, A I Ulyanov, E. S. GorkunovAbstract:The change in the Coercive Force under biaxial asymmetric (tension and compression in mutually perpendicular directions) cyclic deformation of cross-shaped steel 3 specimens in the elastic region of deformations was studied. Specimens were deformed beforehand under biaxial asymmetric loading to various degrees of plastic deformation. It was demonstrated that the elastic-deformation dependences of the Coercive Force measured along the tension and compression directions are qualitatively similar to those under uniaxial tension or compression. It was also shown that, under cyclic elastic loading, these dependences are reversible for well-annealed steel and have a hysteresis that expands with increasing degree of plastic deformation for plastically deformed steel. The possible causes of the hysteresis in the dependence of the Coercive Force on the elastic cyclic deformations under biaxial loading are discussed. It was supposed that the hysteresis of the Coercive Force was caused by the appearance of free (not bound in carbide phases) carbon atoms playing the role of interstitial impurity atoms for the α-iron lattice in plastically deformed carbon steels. The possibility of estimating the stressed-strained state of steel under biaxial loading using a magnetic method was discussed.
V. A. Zakharov - One of the best experts on this subject based on the ideXlab platform.
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Coercive Force of low carbon steels during elastic and plastic tensile deformation
Russian Physics Journal, 2015Co-Authors: A I Ulyanov, V. A. Zakharov, I G PospelovaAbstract:Dependences of the Coercive Force of samples of St3-grade steel (with chemical composition Fe–0.324C–0.187Si–0.457Mn–0.026Cr–0.029Cu–0.008Co) during elastic and plastic tensile deformation are investigated. It is demonstrated that in the region of small deformations, plastic deformation is non-uniform over the length of the operating part of the sample. For well-annealed steel, the dependences of the Coercive Force on the elastic sample deformation became reversible, and for plastically deformed steel, a hysteresis is observed that increases with the degree of plastic deformation of the samples. Possible reasons for the hysteresis of the dependence of the Coercive Force on the elastic cyclic tensile deformations are discussed.
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Coercive-Force hysteresis of carbon steels during elastic cyclic tensile deformation
Russian Journal of Nondestructive Testing, 2013Co-Authors: V. A. Zakharov, A. I. Ul’yanov, E. S. Gorkunov, V. V. VelichkoAbstract:Dependences of the Coercive Force and mechanical stresses on cyclic tensile in the region of elastic deformation of steel samples with various carbon contents (Armco iron, 3, 8) are investigated. It is shown that the dependence of the Coercive Force on cyclic elastic tensile deformation is reversible for well-annealed samples. The dependence for plastically deformed steels has a hysteresis loop that is significantly determined by the carbon content and increases with an increasing degree of plastic deformation. It is assumed that the hysteresis of the Coercive Force as a function of elastic cyclic tensile deformations in plastically deformed carbon steels is caused generally by the appearance “free” carbon atoms, i.e., those not bound in carbide phases, which act as interstitial impurity atoms in the lattice of α-iron.
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Coercive Force of ferromagnetic steels under the biaxial symmetrical tension of a material
Russian Journal of Nondestructive Testing, 2011Co-Authors: V. A. Zakharov, A. I. Ul’yanov, E. S. GorkunovAbstract:Patterns of Coercive Force variations of C t .3 and X70 ferromagnetic steels under biaxial symmetrical tension within both elastic and plastic ranges of deformation were studied using X-shaped specimens. It was shown that the Coercive Force of isotropic polycrystalline materials increased during plastic deformation under biaxial symmetrical tension and was proportional to applied stresses (loads). Plastic deformation of materials with high initial Coercive-Force anisotropy along the principal directions (X70 steel) leads to an abrupt decrease in anisotropy and subsequent alternation of its sign. The patterns of a material’s Coercive Force behavior allow the Coercive Force to be used for estimating the stress-strain state (from both an increase in the Coercive Force and its variations during loading as compared to that of the initial material) of articles made from the studied steels under biaxial symmetrical tensile deformation.
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regularities of the change in the Coercive Force under biaxial asymmetric deformation of steel 3
Russian Journal of Nondestructive Testing, 2010Co-Authors: V. A. Zakharov, A I Ulyanov, E. S. GorkunovAbstract:The change in the Coercive Force under biaxial asymmetric (tension and compression in mutually perpendicular directions) cyclic deformation of cross-shaped steel 3 specimens in the elastic region of deformations was studied. Specimens were deformed beforehand under biaxial asymmetric loading to various degrees of plastic deformation. It was demonstrated that the elastic-deformation dependences of the Coercive Force measured along the tension and compression directions are qualitatively similar to those under uniaxial tension or compression. It was also shown that, under cyclic elastic loading, these dependences are reversible for well-annealed steel and have a hysteresis that expands with increasing degree of plastic deformation for plastically deformed steel. The possible causes of the hysteresis in the dependence of the Coercive Force on the elastic cyclic deformations under biaxial loading are discussed. It was supposed that the hysteresis of the Coercive Force was caused by the appearance of free (not bound in carbide phases) carbon atoms playing the role of interstitial impurity atoms for the α-iron lattice in plastically deformed carbon steels. The possibility of estimating the stressed-strained state of steel under biaxial loading using a magnetic method was discussed.
Yutaka Matsuura - One of the best experts on this subject based on the ideXlab platform.
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Relation between the alignment dependence of Coercive Force decrease ratio and the angular dependence of Coercive Force of ferrite magnets
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Yutaka Matsuura, Nobuyuki Kitai, Seiichi Hosokawa, Jun HoshijimaAbstract:Abstract The relation of the Coercive Force decrease ratio (CFDR) and the angular dependence of the Coercive Force (ADCF) of ferrite magnets and their temperature properties were investigated. When we compared that against the angle of the magnetization reverse area obtained from these calculation results, which was obtained from the Gaussian distribution of the grain alignment and the postulation that every grain follows the Kondorskii law or the 1/cos θ law, and against the angle of the reverse magnetization area calculated from the experiment CFDR data of these magnets, it was found that this latter expanded at room temperature, to 36° from the calculated angle, for magnet with α=0.96. It was also found that, as temperature increased from room temperature to 413 K, the angle of the reverse magnetization area of ferrite magnets obtained from the experiment data expanded from 36° to 41°. When we apply these results to the temperature properties of ADCF, it seems that the calculated ADCF could qualitatively and reasonably explain these temperature properties, even though the difference between the calculated angular dependence and the experimental data still exists in the high angle range. These results strongly suggest that the Coercive Force of these magnets is determined by the magnetic domain wall motion. The magnetic domain walls are strongly pinned at tilted grains, and when the domain walls are de-pinned from their pinning sites, the Coercive Force is determined.
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temperature properties of the alignment dependence of Coercive Force decrease ratio and the angular dependence of Coercive Force in nd fe b sintered magnets
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro Ishii, Nobuyuki Kitai, Mitsutoshi Natsumeda, Futoshi KuniyoshiAbstract:Abstract The temperature dependence of the Coercive Force decrease ratio for aligned magnets was investigated from room temperature (296 K) to 473 K. The temperature properties of the angular dependence of the Coercive Force were also measured from room temperature to 413 K, for comparison against the Coercive Force decrease ratio. From the temperature dependence of the Coercive Force decrease ratio of magnets with different alignment, it was found that the Coercive Force decrease ratio decreased as temperature increased until becoming close to the calculation results that were obtained from the Gaussian distribution for Nd 2 Fe 14 B grain alignment and from the postulation that every grain follows the Kondorskii law or the 1/cos θ law. When we compared the angle of the magnetization reverse area obtained from these calculation results and the angle of the reverse magnetization area calculated from the experimental data of the Coercive Force decrease ratio, it was found that this latter expanded to 30° for Nd 13.48 B 5.76 Co 0.55 Fe bal. having 0.95 alignment, at room temperature, from 14° that was the calculated angle obtained from the Gaussian distribution and the Kondorskii law. The angular dependence of Coercive Force of this magnet at room temperature agrees well with the calculation, when σ =31°, which is 30° for the reversed magnetization area, is applied as the standard deviation of Nd 2 Fe 14 B grain alignment distribution. For Nd 12.75 Dy 0.84 B 5.81 Co 0.55 Fe bal. with 0.96 for alignment, the reverse magnetization area also expanded to 36° and agreed well with the calculation result applied σ =44°, which has 36° for the reverse magnetization area. It was also found that, as temperature increased, the angle of the reverse magnetization area obtained from the experimental data shrunk towards the calculated angle. When we apply these results to the temperature properties of the angular dependence of the Coercive Force, it seems that the calculated angular dependence of the Coercive Force can qualitatively and reasonably explain these temperature properties. These results strongly suggest that the magnetic domain walls are strongly pinned at tilted grains. It also suggests that, when such magnetic domain walls are de-pinned from their pinning sites, they leap through several grains with weak pinning Force, which determines the Coercive Force.
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recoil curve properties and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Rintaro Ishii, Nobuyuki Kitai, Toshimitsu Natsumeda, Jun HoshijimaAbstract:It is examined that whether a reverse domain and magnetic domain wall exist in a lower demagnetization area than the Coercive Force and whether the observed demagnetization ratio curve can be explained using the alignment distribution function or not. From measurements of the recoil curve in the low demagnetization field, it was confirmed that minor demagnetization occurred in every demagnetization field and magnets of every grade of Coercive Force. The alignment distribution of Nd2Fe14B grains was also measured by electron back-scattering diffraction (EBSD). The alignments and the Coercive Force decrease ratios were calculated using these alignment distributions. These data were compared against the results obtained from magnetization measurements. From EBSD data, it was found that the alignment distributions of magnets used in this experiment were close to a Gaussian distribution. It was also found that there was no difference in the alignment distribution between magnets with Dy and without Dy, even though the Coercive Force decrease ratios were Dy dependent. The calculated alignments using the alignment distribution functions were close to the values of magnetization measurements. However, it was found that the calculated Coercive Force decrease ratios were different from the results obtained from magnetization measurement.
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relation between nd2fe14b grain alignment and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro IshiiAbstract:Abstract It was found that the Coercive Force of NdFeB sintered magnets decreases as the Nd 2 Fe 14 B grain alignment improves. Because of this phenomenon, studies looked at the relation between this alignment and the Coercive Force decrease ratio. In experiments, it was expected that the Coercive Force of perfectly aligned magnet reached 0.7 of Coercive Force in istotropically aligned magnet. When it is postulated that the Coercive Force is determined by the Stoner–Wohlfarth model, Coercive Force increases as the alignment improves and it becomes difficult to explain our experimental data. On the other hand, when the Coercive Force is determined by magnetic domain wall motion, the Coercive Force decreases as the alignment improves and the Coercive Force of the perfectly aligned magnet reaches 1 / 2 of the isotropically aligned magnet. This tendency and value was very close to our data. It strongly suggests that the Coercive Force of NdFeB sintered magnets is determined by the domain wall motion.
Jun Hoshijima - One of the best experts on this subject based on the ideXlab platform.
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Relation between the alignment dependence of Coercive Force decrease ratio and the angular dependence of Coercive Force of ferrite magnets
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Yutaka Matsuura, Nobuyuki Kitai, Seiichi Hosokawa, Jun HoshijimaAbstract:Abstract The relation of the Coercive Force decrease ratio (CFDR) and the angular dependence of the Coercive Force (ADCF) of ferrite magnets and their temperature properties were investigated. When we compared that against the angle of the magnetization reverse area obtained from these calculation results, which was obtained from the Gaussian distribution of the grain alignment and the postulation that every grain follows the Kondorskii law or the 1/cos θ law, and against the angle of the reverse magnetization area calculated from the experiment CFDR data of these magnets, it was found that this latter expanded at room temperature, to 36° from the calculated angle, for magnet with α=0.96. It was also found that, as temperature increased from room temperature to 413 K, the angle of the reverse magnetization area of ferrite magnets obtained from the experiment data expanded from 36° to 41°. When we apply these results to the temperature properties of ADCF, it seems that the calculated ADCF could qualitatively and reasonably explain these temperature properties, even though the difference between the calculated angular dependence and the experimental data still exists in the high angle range. These results strongly suggest that the Coercive Force of these magnets is determined by the magnetic domain wall motion. The magnetic domain walls are strongly pinned at tilted grains, and when the domain walls are de-pinned from their pinning sites, the Coercive Force is determined.
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temperature properties of the alignment dependence of Coercive Force decrease ratio and the angular dependence of Coercive Force in nd fe b sintered magnets
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro Ishii, Nobuyuki Kitai, Mitsutoshi Natsumeda, Futoshi KuniyoshiAbstract:Abstract The temperature dependence of the Coercive Force decrease ratio for aligned magnets was investigated from room temperature (296 K) to 473 K. The temperature properties of the angular dependence of the Coercive Force were also measured from room temperature to 413 K, for comparison against the Coercive Force decrease ratio. From the temperature dependence of the Coercive Force decrease ratio of magnets with different alignment, it was found that the Coercive Force decrease ratio decreased as temperature increased until becoming close to the calculation results that were obtained from the Gaussian distribution for Nd 2 Fe 14 B grain alignment and from the postulation that every grain follows the Kondorskii law or the 1/cos θ law. When we compared the angle of the magnetization reverse area obtained from these calculation results and the angle of the reverse magnetization area calculated from the experimental data of the Coercive Force decrease ratio, it was found that this latter expanded to 30° for Nd 13.48 B 5.76 Co 0.55 Fe bal. having 0.95 alignment, at room temperature, from 14° that was the calculated angle obtained from the Gaussian distribution and the Kondorskii law. The angular dependence of Coercive Force of this magnet at room temperature agrees well with the calculation, when σ =31°, which is 30° for the reversed magnetization area, is applied as the standard deviation of Nd 2 Fe 14 B grain alignment distribution. For Nd 12.75 Dy 0.84 B 5.81 Co 0.55 Fe bal. with 0.96 for alignment, the reverse magnetization area also expanded to 36° and agreed well with the calculation result applied σ =44°, which has 36° for the reverse magnetization area. It was also found that, as temperature increased, the angle of the reverse magnetization area obtained from the experimental data shrunk towards the calculated angle. When we apply these results to the temperature properties of the angular dependence of the Coercive Force, it seems that the calculated angular dependence of the Coercive Force can qualitatively and reasonably explain these temperature properties. These results strongly suggest that the magnetic domain walls are strongly pinned at tilted grains. It also suggests that, when such magnetic domain walls are de-pinned from their pinning sites, they leap through several grains with weak pinning Force, which determines the Coercive Force.
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recoil curve properties and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Rintaro Ishii, Nobuyuki Kitai, Toshimitsu Natsumeda, Jun HoshijimaAbstract:It is examined that whether a reverse domain and magnetic domain wall exist in a lower demagnetization area than the Coercive Force and whether the observed demagnetization ratio curve can be explained using the alignment distribution function or not. From measurements of the recoil curve in the low demagnetization field, it was confirmed that minor demagnetization occurred in every demagnetization field and magnets of every grade of Coercive Force. The alignment distribution of Nd2Fe14B grains was also measured by electron back-scattering diffraction (EBSD). The alignments and the Coercive Force decrease ratios were calculated using these alignment distributions. These data were compared against the results obtained from magnetization measurements. From EBSD data, it was found that the alignment distributions of magnets used in this experiment were close to a Gaussian distribution. It was also found that there was no difference in the alignment distribution between magnets with Dy and without Dy, even though the Coercive Force decrease ratios were Dy dependent. The calculated alignments using the alignment distribution functions were close to the values of magnetization measurements. However, it was found that the calculated Coercive Force decrease ratios were different from the results obtained from magnetization measurement.
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relation between nd2fe14b grain alignment and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro IshiiAbstract:Abstract It was found that the Coercive Force of NdFeB sintered magnets decreases as the Nd 2 Fe 14 B grain alignment improves. Because of this phenomenon, studies looked at the relation between this alignment and the Coercive Force decrease ratio. In experiments, it was expected that the Coercive Force of perfectly aligned magnet reached 0.7 of Coercive Force in istotropically aligned magnet. When it is postulated that the Coercive Force is determined by the Stoner–Wohlfarth model, Coercive Force increases as the alignment improves and it becomes difficult to explain our experimental data. On the other hand, when the Coercive Force is determined by magnetic domain wall motion, the Coercive Force decreases as the alignment improves and the Coercive Force of the perfectly aligned magnet reaches 1 / 2 of the isotropically aligned magnet. This tendency and value was very close to our data. It strongly suggests that the Coercive Force of NdFeB sintered magnets is determined by the domain wall motion.
Rintaro Ishii - One of the best experts on this subject based on the ideXlab platform.
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temperature properties of the alignment dependence of Coercive Force decrease ratio and the angular dependence of Coercive Force in nd fe b sintered magnets
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro Ishii, Nobuyuki Kitai, Mitsutoshi Natsumeda, Futoshi KuniyoshiAbstract:Abstract The temperature dependence of the Coercive Force decrease ratio for aligned magnets was investigated from room temperature (296 K) to 473 K. The temperature properties of the angular dependence of the Coercive Force were also measured from room temperature to 413 K, for comparison against the Coercive Force decrease ratio. From the temperature dependence of the Coercive Force decrease ratio of magnets with different alignment, it was found that the Coercive Force decrease ratio decreased as temperature increased until becoming close to the calculation results that were obtained from the Gaussian distribution for Nd 2 Fe 14 B grain alignment and from the postulation that every grain follows the Kondorskii law or the 1/cos θ law. When we compared the angle of the magnetization reverse area obtained from these calculation results and the angle of the reverse magnetization area calculated from the experimental data of the Coercive Force decrease ratio, it was found that this latter expanded to 30° for Nd 13.48 B 5.76 Co 0.55 Fe bal. having 0.95 alignment, at room temperature, from 14° that was the calculated angle obtained from the Gaussian distribution and the Kondorskii law. The angular dependence of Coercive Force of this magnet at room temperature agrees well with the calculation, when σ =31°, which is 30° for the reversed magnetization area, is applied as the standard deviation of Nd 2 Fe 14 B grain alignment distribution. For Nd 12.75 Dy 0.84 B 5.81 Co 0.55 Fe bal. with 0.96 for alignment, the reverse magnetization area also expanded to 36° and agreed well with the calculation result applied σ =44°, which has 36° for the reverse magnetization area. It was also found that, as temperature increased, the angle of the reverse magnetization area obtained from the experimental data shrunk towards the calculated angle. When we apply these results to the temperature properties of the angular dependence of the Coercive Force, it seems that the calculated angular dependence of the Coercive Force can qualitatively and reasonably explain these temperature properties. These results strongly suggest that the magnetic domain walls are strongly pinned at tilted grains. It also suggests that, when such magnetic domain walls are de-pinned from their pinning sites, they leap through several grains with weak pinning Force, which determines the Coercive Force.
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recoil curve properties and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Rintaro Ishii, Nobuyuki Kitai, Toshimitsu Natsumeda, Jun HoshijimaAbstract:It is examined that whether a reverse domain and magnetic domain wall exist in a lower demagnetization area than the Coercive Force and whether the observed demagnetization ratio curve can be explained using the alignment distribution function or not. From measurements of the recoil curve in the low demagnetization field, it was confirmed that minor demagnetization occurred in every demagnetization field and magnets of every grade of Coercive Force. The alignment distribution of Nd2Fe14B grains was also measured by electron back-scattering diffraction (EBSD). The alignments and the Coercive Force decrease ratios were calculated using these alignment distributions. These data were compared against the results obtained from magnetization measurements. From EBSD data, it was found that the alignment distributions of magnets used in this experiment were close to a Gaussian distribution. It was also found that there was no difference in the alignment distribution between magnets with Dy and without Dy, even though the Coercive Force decrease ratios were Dy dependent. The calculated alignments using the alignment distribution functions were close to the values of magnetization measurements. However, it was found that the calculated Coercive Force decrease ratios were different from the results obtained from magnetization measurement.
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relation between nd2fe14b grain alignment and Coercive Force decrease ratio in ndfeb sintered magnets
Journal of Magnetism and Magnetic Materials, 2013Co-Authors: Yutaka Matsuura, Jun Hoshijima, Rintaro IshiiAbstract:Abstract It was found that the Coercive Force of NdFeB sintered magnets decreases as the Nd 2 Fe 14 B grain alignment improves. Because of this phenomenon, studies looked at the relation between this alignment and the Coercive Force decrease ratio. In experiments, it was expected that the Coercive Force of perfectly aligned magnet reached 0.7 of Coercive Force in istotropically aligned magnet. When it is postulated that the Coercive Force is determined by the Stoner–Wohlfarth model, Coercive Force increases as the alignment improves and it becomes difficult to explain our experimental data. On the other hand, when the Coercive Force is determined by magnetic domain wall motion, the Coercive Force decreases as the alignment improves and the Coercive Force of the perfectly aligned magnet reaches 1 / 2 of the isotropically aligned magnet. This tendency and value was very close to our data. It strongly suggests that the Coercive Force of NdFeB sintered magnets is determined by the domain wall motion.