Characterization methods of grain boundary and triple junction distributions

Yi, Yongsun; Kim, J.S.

doi:10.1016/j.scriptamat.2003.12.010

Cited by 8 publications

(9 citation statements)

References 6 publications

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“…Here, 𝑫 ̃ * and 𝑾 ̃ * are given by: 𝑫 ̃ * = sym(𝐂 ̃𝑒𝛀 ̃𝑒) + 𝑹 𝑒 𝑫 ̅ 𝑝 𝑹 𝑒 𝑇 , 𝑾 ̃ * = skew(𝐂 ̃𝑒𝛀 ̃𝑒) + 𝑹 𝑒 𝑾 ̅̅̅ 𝑝 𝑹 𝑒 𝑇 (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) where 𝐂 ̃𝑒 = 𝑽 𝑒 𝑇 𝑽 𝑒 and, in the next equation, 𝑪 ̅ 𝑒 = 𝑭 𝑒 𝑇 𝑭 𝑒 are the elastic right Cauchy-Green tensors, and 𝑫 ̅ 𝑝 and 𝑾 ̅̅̅ 𝑝 are defined below:…”

Section: Constitutive Model 21 Updated Kinematicsmentioning

confidence: 99%

“…It can be seen in (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) that the rate of deformation tensor due to plastic deformation, 𝑫 ̅ 𝑝 , depends on both the slip and void growth based plastic deformations, but the spin tensor only depends on the deformation due to slip, because void growth does not change the shape of the lattice.…”

Section: Constitutive Model 21 Updated Kinematicsmentioning

confidence: 99%

“…The definition of 𝑳 ̃ given in (2)(3)(4)(5)(6)(7)(8)(9)(10)(11) along with 𝑫 ̃= sym(𝑪 ̃𝑒𝑳 ̃) can be used to get 𝑫 ̃= 𝑽 𝑒 𝑇 𝒅𝑽 𝑒 in which the value of 𝒅 can then be substituted from (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) to get:…”

Section: Constitutive Model 21 Updated Kinematicsmentioning

confidence: 99%

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A multiscale constitutive model for metal forming of dual phase titanium alloys by incorporating inherent deformation and failure mechanisms

Asim¹,

Siddiq²,

McMeeking³

et al. 2022

Modelling Simul. Mater. Sci. Eng.

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Ductile metals undergo a considerable amount of plastic deformation before failure. Void nucleation, growth and coalescence is the mechanism of failure in such metals. α–β titanium alloys are ductile in nature and are widely used for their unique set of properties such as specific strength, fracture toughness, corrosion resistance and resistance to fatigue failures. Voids in these alloys have been reported to nucleate on the phase boundaries between α and β phase. Based on the findings of crystal plasticity finite element method investigations of the void growth at the interface of α and β phases, a void nucleation, growth, and coalescence model has been formulated. An existing single-phase crystal plasticity theory is extended to incorporate underlying physical mechanisms of deformation and failure in dual phase titanium alloys. Effects of various factors [stress triaxiality, Lode parameter, deformation state (equivalent stress), and phase boundary inclination] on void nucleation, growth and coalescence are used to formulate a phenomenological constitutive model while their interaction with a conventional crystal plasticity theory is established. An extensive parametric assessment of the model is carried out to quantify and understand the effects of the material parameters on the overall material response. Performance of the proposed model is then assessed and verified by comparing the results of the proposed model with the RVE study results. Application of the constitutive model for utilisation in the design and optimisation of the forming process of α–β titanium alloy components is also demonstrated using experimental data.

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Section: Constitutive Model 21 Updated Kinematicsmentioning

confidence: 99%

Section: Constitutive Model 21 Updated Kinematicsmentioning

confidence: 99%

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A multiscale constitutive model for metal forming of dual phase titanium alloys by incorporating inherent deformation and failure mechanisms

Asim¹,

Siddiq²,

McMeeking³

et al. 2022

Modelling Simul. Mater. Sci. Eng.

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“…g are called triple junction fractions and denote the population of triple junctions coordinated by i ''special'' grain boundaries [39][40][41][42][43][44][45][46][47], which, for our purposes, correspond to low-angle grain boundaries with diffusivity D 1 . The elements of M are easily measured experimentally using various destructive [48][49][50] or non-destructive [23,[51][52][53][54] crystallographic characterization techniques.…”

Section: Materials Properties Localizationmentioning

confidence: 99%

Inferring grain boundary structure–property relations from effective property measurements

Johnson

Demkowicz

et al. 2015

J Mater Sci

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Grain boundaries strongly affect many materials properties in polycrystalline materials. However, very few structure-property models exist for grain boundaries, due in large part to the complicated and poorly understood way in which the properties of grain boundaries vary with their crystallographic structure. In the present work, we infer grain boundary structure-property correlations from measurements of the effective properties of a polycrystal. We refer to this approach as grain boundary properties localization. We apply this technique to a simple model system of grain boundary diffusivity in a two-dimensional microstructure, and infer the properties of low-and highangle grain boundaries from the effective diffusivity of the grain boundary network. The generalization and use of these methods could greatly reduce the computational and experimental effort required to establish structure-property correlations for grain boundaries. More broadly, the technique of properties localization could be used to infer the properties of many microstructural constituents in complex microstructures.

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“…Similar behavior was reported by Gertsman and Bruemmer 39 for Alloy 600 and by Pan et al 40 for Alloy X-750. In addition to the experimental observations, quite a few modeling studies have been conducted, based primarily on percolation stochastic methods 41,42 or on concepts such as "grain boundary connectivity" 43 that attempt to explain the effect of grain boundary type on crack propagation. Although it is not clear whether models based on either method fully explain the available crack growth data, they all appear to have one common premise: that cracking will propagate along the HABs.…”

Section: Effect Of Grain Boundary Type and Relative Grain Orientationmentioning

confidence: 99%

Crack growth rates of nickel alloy welds in a PWR environment.

Alexandreanu¹,

Chopra²,

Shack³

2006

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In light water reactors (LWRs), vessel internal components made of nickel-base alloys are susceptible to environmentally assisted cracking. A better understanding of the causes and mechanisms of this cracking may permit less conservative estimates of damage accumulation and requirements on inspection intervals. A program is being conducted at Argonne National Laboratory to evaluate the resistance of Ni alloys and their welds to environmentally assisted cracking in simulated LWR coolant environments. This report presents crack growth rate (CGR) results for Alloy 182 shielded-metal-arc weld metal in a simulated pressurized water reactor (PWR) environment at 320°C. Crack growth tests were conducted on 1-T compact tension specimens with different weld orientations from both double-J and deep-groove welds. The results indicate little or no environmental enhancement of fatigue CGRs of Alloy 182 weld metal in the PWR environment. The CGRs of Alloy 182 in the PWR environment are a factor of ≈5 higher than those of Alloy 600 in air under the same loading conditions. The stress corrosion cracking for the Alloy 182 weld is close to the average behavior of Alloy 600 in the PWR environment. The weld orientation was found to have a profound effect on the magnitude of crack growth: cracking was found to propagate faster along the dendrites than across them. The existing CGR data for Ni-alloy weld metals have been compiled and evaluated to establish the effects of key material, loading, and environmental parameters on CGRs in PWR environments. The results from the present study are compared with the existing CGR data for Ni-alloy welds to determine the relative susceptibility of the specific Ni-alloy weld to environmentally enhanced cracking. iv Intentionally Left BlankForeword v This report presents crack growth rate data and the results of the corresponding fracture surface and metallographic examinations from cyclic loading and primary water stress-corrosion cracking (PWSCC) tests of two nickel-base Alloy 182 (A182) weldments, which are typical of those used in vessel penetrations and piping butt welds in nuclear power plants. The effect of crack orientation with respect to dendrite orientation is the most significant variable investigated in this study. However, this report also includes a review of data from several laboratories, which describes the effects of material composition, loading characteristics, and chemistry of the aqueous environment. The main conclusion is that the PWSCC growth rates described for A182 specimens in this report are comparable to the crack growth rates that characterize the performance of Alloy 600 (A600).This report is the first in a series documenting the results of crack growth rate testing in vessel head penetration materials, focusing on the weld metals, A182 and A152, and including results of some tests of the base metals, A600 and (eventually) A690. The results presented in this report were obtained in tests of a laboratory-fabricated, shielded metal arc welding deposit of A182. ...

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Characterization methods of grain boundary and triple junction distributions

Cited by 8 publications

References 6 publications

A multiscale constitutive model for metal forming of dual phase titanium alloys by incorporating inherent deformation and failure mechanisms

A multiscale constitutive model for metal forming of dual phase titanium alloys by incorporating inherent deformation and failure mechanisms

Inferring grain boundary structure–property relations from effective property measurements

Crack growth rates of nickel alloy welds in a PWR environment.

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