Interface Migration with Segregation in MoSi&lt;sub&gt;2&lt;/sub&gt;-Based Lamellar Alloy Simulated by Phase-Field Method

Yamazaki, Toshihiro; Koizumi, Yuichiro; Chiba, Akihiko; Hagihara, Koji; Nakano, Takayoshi; Yuge, Koretaka; Kishida, Kyosuke; Inui, Haruyuki

doi:10.4028/www.scientific.net/amr.922.832

“…Thus, in the present study, we have investigated the differences between the decomposed microstructures formed in the two cases of without rolling (hereafter, denoted by "non-rolled") and with rolling (hereafter, denoted by "rolled") to reveal the effects of dislocations introduced by cold-rolling on the spinodal decomposition of Fe-Cr-Co alloys. In addition, we performed phase-field simulations [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] to discuss the formation mechanisms of the experimentally observed microstructures in terms of defects induced by plastic deformations as a path for rapid diffusion.…”

Section: Introductionmentioning

confidence: 99%

Spinodal Decomposition in Plastically Deformed Fe–Cr–Co Magnet Alloy

Iwaizako

¹

,

Okugawa

²

,

Saito

³

et al. 2022

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Fe-Cr-Co alloys are becoming important as half-hard magnet which can be subjected to plastic deformation process for their novel applications including non-contact electromagnetic brake because of its large hysteresis loss. Its magnetic hardness depends on the modulated structure formed by spinodal decomposition. It is important to clarify the effect of plastic deformation on the spinodal decomposition for optimizing the heat treatment after plastic deformation process. In the present study, we examined the spinodal-decomposed structures in Fe-Cr-Co sheets cold-rolled to 25% reduction and that without rolling to clarify the influences of cold rolling. Also, spinodal decomposition under the presence of dislocation structure have been simulated by phase field method for the case with the presence of dislocation cell boundary with a high in-plane solute diffusivity at various migrating speed. It has been found that the spinodal decomposition is accelerated around dislocation owing to the elastic field and higher diffusivity, which results in inhomogeneous microstructure with various wave length of modulation. The existence of dislocation enhances the initiation of phase decomposition and the growth particles. The decomposed structure greatly depends on the in-plane solute diffusivity and migrating speed of the dislocation cell boundary.

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“…In our previous study, we primarily focused on the segregation mechanism of the additive element. We clarified that the Cr-segregation is largely dependent on the segregation energy, which is the chemical interaction between the solute atoms and the interface which was evaluated by using the first-principles calculation [12][13][14][15][16][17]. Further, we have examined the dominant factor for the formation of lamellar structure [18].…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of lamellar structure formation and Cr interfacial segregation in C11b-MoSi2/C40-NbSi2 dual phase silicide verified by a phase-field simulation incorporating elastic inhomogeneity

Yamazaki

¹

,

Koizumi

²

,

Yuge

³

et al. 2015

Computational Materials Science

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a b s t r a c tWe developed a phase-field model of C11 b -MoSi 2 /C40-NbSi 2 duplex silicide incorporating elastic inhomogeneity, and simulated microstructure formation and interface segregation. We examined the effect of elastic inhomogeneity on the morphology, volume fraction of the C11 b -precipitate, stress distribution, and solute partitioning. In the simulations, parameters evaluated by first-principles calculation are used for the experimentally unknown parameters. The lamellar structure was not formed in the case incorporating the elastic strain energy only and ignoring the anisotropy of the interfacial energy. When the anisotropy of the interfacial energy was taken into account, the lamellar structure was formed parallel to (0 0 0 1) C40 as observed in the experiment. It was also found that the elastic strain energy changes the equilibrium concentrations by >0.2 at%, but the difference between the equilibrium concentrations in homogeneous and inhomogeneous systems was <0.1 at%. The interfacial segregation was also hardly affected by the elastic inhomogeneity. These results confirm that elastic inhomogeneity can be neglected in the simulation of MoSi 2 /NbSi 2 lamellar silicide.

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Spinodal Decomposition in Plastically Deformed Fe-Cr-Co Magnet Alloy

Iwaizako

¹

,

Okugawa

²

,

Saito

³

et al. 2021

Tetsu-to-Hagane

0

1

View full text Add to dashboard Cite

Fe-Cr-Co alloys are becoming important as half-hard magnet which can be subjected to plastic deformation process for their novel applications including non-contact electromagnetic brake because of its large hysteresis loss. Its magnetic hardness depends on the modulated structure formed by spinodal decomposition. It is important to clarify the effect of plastic deformation on the spinodal decomposition for optimizing the heat treatment after plastic deformation process. In the present study, we examined the spinodal-decomposed structures in Fe-Cr-Co sheets cold-rolled to 25% reduction and that without rolling to clarify the influences of cold rolling. Also, spinodal decomposition under the presence of dislocation structure have been simulated by phase field method for the case with the presence of dislocation cell boundary with a high in-plane solute diffusivity at various migrating speed. It has been found that the spinodal decomposition is accelerated around dislocation owing to the elastic field and higher diffusivity, which results in inhomogeneous microstructure with various wave length of modulation. The existence of dislocation enhances the initiation of phase decomposition and the growth particles. The decomposed structure greatly depends on the in-plane solute diffusivity and migrating speed of the dislocation cell boundary.

show abstract

Interface Migration with Segregation in MoSi<sub>2</sub>-Based Lamellar Alloy Simulated by Phase-Field Method

Cited by 3 publications

References 12 publications

Spinodal Decomposition in Plastically Deformed Fe–Cr–Co Magnet Alloy

Spinodal Decomposition in Plastically Deformed Fe–Cr–Co Magnet Alloy

Mechanisms of lamellar structure formation and Cr interfacial segregation in C11b-MoSi2/C40-NbSi2 dual phase silicide verified by a phase-field simulation incorporating elastic inhomogeneity

Spinodal Decomposition in Plastically Deformed Fe-Cr-Co Magnet Alloy

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