Atomistic survey of grain boundary-dislocation interactions in FCC nickel

Adams, Devin; Fullwood, David T.; Wagoner, R. H.; Homer, Eric R.

doi:10.1016/j.commatsci.2019.04.007

Cited by 31 publications

(5 citation statements)

References 67 publications

(126 reference statements)

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“…The development of such a methodology requires, in addition to a sufficiently large data set, the proper selection of descriptors from which the relations will be created. Grain boundary studies utilizing large sets of grain boundaries have been performed for a variety of material properties, including grain boundary energy, , mobility, and mechanical response . However, models built from these studies have generally been developed from either a strictly macroscopic perspective, − considering only properties such as crystallographic orientation or elastic tensor values, or a microscopic perspective, by relating the atomic structure to the property under consideration .…”

Section: Introductionmentioning

confidence: 99%

Microscopic and Macroscopic Characterization of Grain Boundary Energy and Strength in Silicon Carbide via Machine-Learning Techniques

Guziewski

Zapiain

Dingreville

et al. 2021

ACS Appl. Mater. Interfaces

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Predicting the properties of grain boundaries poses a challenge because of the complex relationships between structural and chemical attributes both at the atomic and continuum scales. Grain boundary systems are typically characterized by parameters used to classify local atomic arrangements in order to extract features such as grain boundary energy or grain boundary strength. The present work utilizes a combination of high-throughput atomistic simulations, macroscopic and microscopic descriptors, and machine-learning techniques to characterize the energy and strength of silicon carbide grain boundaries. A diverse data set of symmetric tilt and twist grain boundaries are described using macroscopic metrics such as misorientation, the alignment of critical low-index planes, and the Schmid factor, but also in terms of microscopic metrics, by quantifying the local atomic structure and chemistry at the interface. These descriptors are used to create random-forest regression models, allowing for their relative importance to the grain boundary energy and decohesion stress to be better understood. Results show that while the energetics of the grain boundary were best described using the microscopic descriptors, the ability of the macroscopic descriptors to reasonably predict grain boundaries with low energy suggests a link between the crystallographic orientation and the resultant atomic structure that forms at the grain boundary within this regime. For grain boundary strength, neither microscopic nor macroscopic descriptors were able to fully capture the response individually. However, when both descriptor sets were utilized, the decohesion stress of the grain boundary could be accurately predicted. These results highlight the importance of considering both macroscopic and microscopic factors when constructing constitutive models for grain boundary systems, which has significant implications for both understanding the fundamental mechanisms at work and the ability to bridge length scales.

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Section: Introductionmentioning

confidence: 99%

Microscopic and Macroscopic Characterization of Grain Boundary Energy and Strength in Silicon Carbide via Machine-Learning Techniques

Guziewski

Zapiain

Dingreville

et al. 2021

ACS Appl. Mater. Interfaces

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“…These include characterizations of the GB itself such as GB tilt etc. [1][2][3][4][5], as well as characteristics of the grains on either side of the GB such as relative misorientation etc. [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…This slip "transmission" can also be considered activation of slip in the neighboring grain. However, it will be referred to as transmission in this paper as it is the term often used in the literature to reference this phenomenon [1,2,5,18]. Hence the fundamental question arises as to whether the observed pileup and / or the transmission (as described by pushing dislocations through a GB as well as activation of slip in neighbor grain) behavior at GBs correlates with GB obstacle strength.…”

Section: Introductionmentioning

confidence: 99%

Slip band characteristics in the presence of grain boundaries in nickel-based superalloy

et al. 2020

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Shear strain profiles along slip bands in a modified Rolls-Royce nickel superalloy (RR1000) were analyzed for a tensile sample deformed by 2%. The strain increased with distance away from a grain boundary (GB), with maximum shear strain towards the center of the grain, indicating that dislocation nucleation generally occurred in the grain interior. The strain gradients in the neighborhood of the GBs were quantified and generally correlated with rotation about the active slip system line direction. This leads to an ability to determine the active slip system in these regions. The dislocation spacing and pileup stresses were inferred. The dislocation spacing closely follows an Eshelby analytical solution for a single ended pileup of dislocations under an applied stress. The distribution of pileup stress values for GBs of a given misorientation angle follows a log-normal distribution, with no correlation between the pileup stress and the GB misorientation angle. Furthermore, there is no observed correlation between various transmissivity factors and slip band pileup stress. Hence it appears that the obstacle strength of any of the observed GBs is adequate to facilitate the dislocation pileups present in the slip bands. However, slip band transmission does correlate with transmissivity factors, with the current study focusing on the Luster and Morris m'-factor. Observation of strain profiles of transmitted bands indicate dislocation nucleation locations.

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“…These resistances may greatly reduce the penetration rate of the dislocations, causing a large amount of plugging of the dislocations at the LAGBs, which ultimately leads to higher strengths. [18,[34][35][36][37][38][39] 3.4.3. High-Angle Grain Boundary Strengthening…”

Section: Low-angle Grain Boundary Strengtheningmentioning

confidence: 99%

Microstructural Evolution and Mechanical Properties of Sn‐58Bi Solder Alloys with Different Cooling

et al. 2021

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Herein, influences of air-cooling, water-cooling, and liquid nitrogen-cooling (LN-cooling) on microstructures and mechanical properties of Sn-58Bi alloy are studied. It is observed that nearly complete eutectic structures are obtained in aircooled Sn-58Bi alloy. Fine grains and many low-angle grain boundaries (LAGBs) are obtained in water-cooled Sn-58Bi alloy. The LN-cooling method causes Bi atoms to form large, regular rectangular shapes, and there are many high-angle grain boundaries (HAGBs) distributed inside the specimen. Impact tests are performed at room temperature. When the impact rate is 0.98 m s À1 , the fracture energy of the water-cooled Sn-58Bi alloy peaks to 71.5 mJ. The fracture of the LN-cooled impact specimen has a large cleavage step due to the interaction of cleavage cracks and the HAGBs. These experimental results lay the relevant theoretical foundation for the practical application of Sn-58Bi solder alloys.

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Atomistic survey of grain boundary-dislocation interactions in FCC nickel

Cited by 31 publications

References 67 publications

Microscopic and Macroscopic Characterization of Grain Boundary Energy and Strength in Silicon Carbide via Machine-Learning Techniques

Microscopic and Macroscopic Characterization of Grain Boundary Energy and Strength in Silicon Carbide via Machine-Learning Techniques

Slip band characteristics in the presence of grain boundaries in nickel-based superalloy

Microstructural Evolution and Mechanical Properties of Sn‐58Bi Solder Alloys with Different Cooling

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