Decohesion of iron grain boundaries by sulfur or phosphorous segregation: First-principles calculations

Yamaguchi, Masatake; Nishiyama, Yutaka; Kaburaki, Hideo

doi:10.1103/physrevb.76.035418

Cited by 83 publications

(67 citation statements)

References 17 publications

(14 reference statements)

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“…There have been a number of recent studies using both first principles and molecular dynamic simulations that have examined how solutes and impurities segregate to grain boundaries within bcc metals. [40][41][42][43][44][45][46][47] Despite this fact, there have been relatively few studies that have focused on He interactions with grain boundaries. [48][49][50][51][52][53][54][55][56][57][58] These prior works have been significant for understanding the migration paths and mechanisms of He for a few boundaries using the dimer method, 49,51 understanding migration of interstitial He in different grain boundaries using molecular dynamics, 52 understanding how the grain boundary strength is affected by He 53,54 or He bubbles, 55 or understanding the diffusion and stability of He defects in grain boundaries using first principles.…”

Section: Introductionmentioning

confidence: 99%

Binding of HenV clusters to α-Fe grain boundaries

Tschopp

Gao

Solanki³

2014

Journal of Applied Physics

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Articles you may be interested inBinding energetics of substitutional and interstitial helium and di-helium defects with grain boundary structure in - The objective of this research is to explore the formation/binding energetics and length scales associated with the interaction between He n V clusters and grain boundaries in bcc a-Fe. In this work, we calculated formation/binding energies for 1-8 He atoms in a monovacancy at all potential grain boundary (GB) sites within 15 Å of the ten grain boundaries selected (122106 simulations total). The present results provide detailed information about the interaction energies and length scales of 1-8 He atoms with grain boundaries for the structures examined. A number of interesting new findings emerge from the present study. First, the R3(112) "twin" GB has significantly lower binding energies for all He n V clusters than all other boundaries in this study. For all grain boundary sites, the effect of the local environment surrounding each site on the He n V formation and binding energies decreases with an increasing number of He atoms in the He n V cluster. Based on the calculated dataset, we formulated a model to capture the evolution of the formation and binding energy of He n V clusters as a function of distance from the GB center, utilizing only constants related to the maximum binding energy and the length scale. V C 2014 AIP Publishing LLC.

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Section: Introductionmentioning

confidence: 99%

Binding of HenV clusters to α-Fe grain boundaries

Tschopp

Gao

Solanki³

2014

Journal of Applied Physics

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“…[1][2][3][4][5][6] Freeman and colleagues 3,4) showed by first-principles calculations that the enhanced intergranular embrittlement by P segregation is related to the embeddedlike electrostatic characteristics. Also, Yamaguchi et al 5,7,8) explained the enhanced GB embrittlement by P and S segregation on the base of the Rice-Wang model. 9) However, there are still some unsolved problems on mechanisms of the GB embrittlement enhanced by impurity segregation, for example, the first site for bond breaking.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Study on Enhanced Grain Boundary Embrittlement of Iron by Phosphorus Segregation

Yuasa

Mabuchi

2011

Mater. Trans.

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It is known that segregation of P atoms at grain boundaries (GB) enhances the intergranular embrittlement in Fe. In the present work, firstprinciples tensile tests have been performed on two bcc Fe cell models with a AE3 ð111Þ=½1 " 1 10 tilt GB: the cell model without P segregation at the GB (clean GB model) and the cell model with P segregation at the GB (P-segregated GB model). The tensile strength and the strain to failure in the P-segregated GB model were 6% and 13% lower than those in the clean GB model. The first bond breaking occurred at the Fe-P bond due to the covalent-like characteristics, although the charge densities were high at the Fe-P bonds. This premature bond breaking of Fe-P was independent of the location of the P atom.

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“…39 It is noted that Si segregation does not seem to induce serious weakening or embrittlement of Fe GBs, which is different from the cases of S and P segregation. 40 The reduction in the adhesion energies of Si-segregated GBs compared to pure Fe GBs is rather small as examined in ref. 36.…”

Section: C) E S Is In Units Of Ev/si Atommentioning

confidence: 98%

Mechanical properties of Fe-rich Si alloy from Hamiltonian

et al. 2017

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The physical origins of the mechanical properties of Fe-rich Si alloys are investigated by combining electronic structure calculations with statistical mechanics means such as the cluster variation method, molecular dynamics simulation, etc, applied to homogeneous and heterogeneous systems. Firstly, we examined the elastic properties based on electronic structure calculations in a homogeneous system and attributed the physical origin of the loss of ductility with increasing Si content to the combined effects of magneto-volume and D0 3 ordering. As a typical example of a heterogeneity forming a microstructure, we focus on grain boundaries, and segregation behavior of Si atoms is studied through high-precision electronic structure calculations. Two kinds of segregation sites are identified: looser and tighter sites. Depending on the site, different segregation mechanisms are revealed. Finally, the dislocation behavior in the Fe-Si alloy is investigated mainly by molecular dynamics simulations combined with electronic structure calculations. The solid-solution hardening and softening are interpreted in terms of two kinds of energy barriers for kink nucleation and migration on a screw dislocation line. Furthermore, the clue to the peculiar work hardening behavior is discussed based on kinetic Monte Carlo simulations by focusing on the preferential selection of slip planes triggered by kink nucleation.npj Computational Materials (2017) 3:10 ; doi:10.1038/s41524-017-0012-4 INTRODUCTION Mechanical properties of alloys originate from the behavior of electrons and atoms on the microscopic scale; however, the strength of atomic bonding does not directly relate to macroscopic mechanical properties such as the yield strength, fracture toughness, and fatigue resistance. This is because the microstructure on the mesoscale, which is composed of various defects such as impurities, grain boundaries, and dislocations, mediates or enhances the response of alloys against external forces, leading to fairly nonlinear and multiscale phenomena. Facing such a nonlinear nature associated with the strength and plastic deformation of alloys, identifying the controlling factors for the mechanical properties is a significantly difficult task, and clarifying the underlying physics at different length and time scales still remains a major challenge in materials science.The authors of the present article took up the challenge of this complicated problem with their particular theoretical and computational tools unique to each characteristic scale range. These tools are electronic structure calculations, the cluster variation method (CVM) of statistical mechanics, and molecular dynamics (MD) simulations, which may cover the atomic to mesoscopic scale ranges. By virtue of high-performance computers, some of the results obtained by the present calculations achieve a higher precision and reveal a clearer picture than those obtained by ordinary experiments.Among the various mechanical properties, the main focus of the present study is the solid-solut...

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Decohesion of iron grain boundaries by sulfur or phosphorous segregation: First-principles calculations

Cited by 83 publications

References 17 publications

Binding of HenV clusters to α-Fe grain boundaries

Binding of HenV clusters to α-Fe grain boundaries

First-Principles Study on Enhanced Grain Boundary Embrittlement of Iron by Phosphorus Segregation

Mechanical properties of Fe-rich Si alloy from Hamiltonian

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