Effect of solute atoms on grain boundary stability of nanocrystalline Ni–Co alloy

Chen, Xiaotong; Lu, Xuefeng; Ren, Junqiang; Han, Xue; Tang, Fuling; Ding, Yutian

doi:10.1007/s10853-022-08001-1

Cited by 7 publications

(4 citation statements)

References 27 publications

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“…Under low Bi conditions, fewer clusters can effectively hinder the movement of dislocations, making it more difficult for the nanocomposites to slip and thus enhancing their strength and hardness. However, when the Bi content is high, the increase in the number of atomic clusters leads to a sharp increase in the irregularity of the local atomic structure, introducing more dislocations and vacancies, resulting in a reduction in the strength and toughness of the nanocomposites, similar to the findings of Chen et al [55]. Therefore, within the range of 0.15% ∼ 0.45% Bi content, the higher the Bi content, the greater the likelihood of cracks occurring during the shearing process.…”

Section: Effect Of Bi Content On Mechanical Behaviorsupporting

confidence: 82%

Effect of Bi content and temperature on the shear mechanical properties of Fe-Bi nanocomposites: a molecular dynamics study

Li,

Wang,

et al. 2024

Modelling Simul. Mater. Sci. Eng.

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In this study, the effects of Bi content and temperature on the mechanical properties of Fe-Bi nanocomposites were investigated using molecular dynamics simulation. The research reveals that the nanocomposite's shear strength reaches a peak of 3.785 GPa at a Bi content of 0.15%, attributed to the impediment of dislocation movement by twin boundaries during shearing, resulting in a dynamic "Hall-Petch" effect and exceptional shear performance of the material. The abundant twinning induced around Bi phase inclusions introduces orientational disparities within the crystal, leading to grain misalignments, with dislocations in the grains slipping near the twin boundaries. In the nanocomposites, <100>dislocations merely act as initial sites for reactions, reducing their impact on the material's strength and fracture behavior. The maximum stress decreases with increasing temperature while the magnitude of atomic transformations increases. The proportion of atoms at grain boundaries is higher at higher temperatures, and the arrangement of atoms at grain boundaries is more complex. At a temperature of 100K, the dislocation density is highest with the smallest variation, forming a reinforced region within the material. The above results have significant implications for the design of environmentally friendly Bi-containing free-cutting steels.

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Section: Effect Of Bi Content On Mechanical Behaviorsupporting

confidence: 82%

Effect of Bi content and temperature on the shear mechanical properties of Fe-Bi nanocomposites: a molecular dynamics study

Li,

Wang,

et al. 2024

Modelling Simul. Mater. Sci. Eng.

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“…The formation of the dislocation network improves the tensile properties of materials to a certain extent because the interaction of the field forces of each dislocation in the dislocation network leads to the obstruction of the dislocation slip, so greater stress is required to facilitate its sliding. 21 As can be seen from the figure, when the strain is zero, there are more Shockley dislocations in green, followed by the perfect dislocation in blue and other dislocations in red, and they gather and tangle at the grain boundary. As the strain increases, the blue perfect dislocation and the red other dislocation gradually decrease.…”

Section: Resultsmentioning

confidence: 95%

“…From Figure a1–e1, we can see that both the pure Ni and Ni–Co alloys after relaxation produce dislocations at grain boundaries and even form a network of dislocation, as shown in black circles. The formation of the dislocation network improves the tensile properties of materials to a certain extent because the interaction of the field forces of each dislocation in the dislocation network leads to the obstruction of the dislocation slip, so greater stress is required to facilitate its sliding . As can be seen from the figure, when the strain is zero, there are more Shockley dislocations in green, followed by the perfect dislocation in blue and other dislocations in red, and they gather and tangle at the grain boundary.…”

Section: Resultsmentioning

confidence: 98%

Effect of Intragranular Solute Atom Segregation on the Mechanical Properties of the Ni–Co Alloy

Zhang

et al. 2023

J. Phys. Chem. C

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In the present contribution, a certain amount of Co atoms was added to the grains (GI) of nano-polycrystalline Ni by a molecular dynamics method to study the effect of solute atom content on the mechanical properties of the alloy. It was found that the tensile strength and yield strength of the alloy increased with the increase of Co atomic content. With the increase of Co content, the grain boundary atomic potential energy decreased and the grain boundary became more stable. As the strain increased, the Co atoms in the grain migrated to the grain boundary, the lattice distortion at the grain boundary increased, and the dislocation nucleation at the grain boundary increased, forming a stable dislocation network and hindering the grain boundary migration. The 1/6⟨112⟩ Shockley incomplete dislocation formed at the grain boundary became the stacking fault source, which was also the source of transformation from the internal stacking fault to the external stacking fault, finally transforming into deformation twins. As the strain increased, the content of Shockley incomplete dislocations in the crystal increased, interacting with other dislocations to dominate the deformation process.

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“…The co-segregation of multiple elements can reduce grain boundary energy and stabilize grain boundary structure more effectively than that of single element. Chen et al [17] simulated the grain boundary precipitation behavior of co atoms in nickel-based alloys, and concluded that adding an appropriate amount of Co atoms at the grain boundary can improve the tensile strength of the material to a certain extent through solution strengthening. Excessive introduction of solute atoms will increase the activity of grain boundary atoms, destroy the stability of grain boundary, and accelerate the emergence of material yield.…”

Section: Introductionmentioning

confidence: 99%

Effect of Cr Segregation on Mechanical Behavior and Deformation Mechanism of Ni─Co─Cr Alloy

Bai,

Chen,

Zhang

et al. 2024

Cryst. Res. Technol.

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Ni─Co alloys have attracted extensive attention from materials researchers in recent years because of their excellent properties. The effect of solute segregation on the properties of the alloy is studied by molecular dynamics simulation. The results show that the yield strength increases from 2.8 to 3.5 GPa when the solute atom Cr is introduced into the grain boundary. Under the action of stress, the disorder of segregation grain boundary is enhanced, which hinders the growth of grain, produces less layer fault structure, and the peak number of HCP (Hexagonal Close Packed) atom decreases from 50 000 to 37 000. The introduction of solute atoms provides a strong support for the grain boundary and has a similar skeleton structure, which improves the deformation resistance of the lattice. In addition, the improved grain boundary stability leads to the difficulty of nucleation of the dislocation, because the obstruction of the grain boundary makes it difficult to activate the dislocation source in the adjacent grain, and the maximum reduction of the perfect dislocation is 74%. In general, the microscopic mechanism of solute segregation strengthening is discussed from dislocation, phase structure, and energy, which provides guidance for plastic deformation of solid‐solution alloys.

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Effect of solute atoms on grain boundary stability of nanocrystalline Ni–Co alloy

Cited by 7 publications

References 27 publications

Effect of Bi content and temperature on the shear mechanical properties of Fe-Bi nanocomposites: a molecular dynamics study

Effect of Bi content and temperature on the shear mechanical properties of Fe-Bi nanocomposites: a molecular dynamics study

Effect of Intragranular Solute Atom Segregation on the Mechanical Properties of the Ni–Co Alloy

Effect of Cr Segregation on Mechanical Behavior and Deformation Mechanism of Ni─Co─Cr Alloy

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