Nanovoid induced multivariant martensitic growth under negative pressure: Effect of misfit strain and temperature on PT threshold stress and phase evolution

Javanbakht, Mahdi; Ghaedi, Mohammad Sadegh

doi:10.1016/j.mechmat.2020.103627

Cited by 20 publications

(4 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An elasto–plastic PF model to study the mechanics of tetragonal-to-monoclinic phase transformation and elasto–plastic deformation of polycrystalline yttria-stabilized tetragonal zirconia was developed by Cissé and Asle Zaeem [ 34 ]. The impact of a pre-existing nanovoid on multi-variant martensitic transformation was investigated by Javanbakht and Ghaedi [ 35 ]. In order to create a pre-existing nanovoid in the model, a single nanovoid was stabilized in the center of the computational domain using a PF approach.…”

Section: Introductionmentioning

confidence: 99%

Interplay of Fracture and Martensite Transformation in Microstructures: A Coupled Problem

2022

View full text Add to dashboard Cite

We are witnessing a tremendous transition towards a society powered by net-zero carbon emission energy, with a corresponding escalating reliance on functional materials (FM). In recent years, the application of FM in multiphysics environments has brought new challenges to the mechanics and materials research communities. The underlying mechanism in FM, which governs several fundamental characteristics, is known as martensitic phase transformation (MPT). When it comes to the application of FM in the multiphysics context, a thorough understanding of the interplay between MPT and fracture plays a crucial role in FM design and application. In the present work, a coupled problem of crack nucleation and propagation and multivariant stress-induced MPT in elastic materials is presented using a finite element method based on Khachaturyan’s microelasticity theory. The problem is established based on a phase-field (PF) approach, which includes the Ginzburg–Landau equations with advanced thermodynamic potential and the variational formulation of Griffith’s theory. Therefore, the model consists of a coupled system of the Ginzburg–Landau equations and the static elasticity equation, and it characterizes evolution of distributions of austenite and two martensitic variants as well as crack growth in terms of corresponding order parameters. The numerical results show that crack growth does not begin until MPT has grown almost completely through the microstructure. Subsequent to the initial formation of the martensite variants, the initial crack propagates in such a way that its path mainly depends on the feature of martensite variant formations, the orientation and direction upon which the martensite plates are aligned, and the stress concentration between martensite plates. In addition, crack propagation behavior and martensite variant evaluations for different lattice orientation angles are presented and discussed in-detail.

show abstract

Section: Introductionmentioning

confidence: 99%

Interplay of Fracture and Martensite Transformation in Microstructures: A Coupled Problem

2022

View full text Add to dashboard Cite

show abstract

“…Examples are the higher-order strain gradient theories [1–7], the rotation gradient or couple-stress theories [8–12] and the nonlocal elasticity theory [13–16]. It is worthy of note that there exists also the phase field theory as a continuum approach, which includes strain nonlocality and has been broadly used for the micro/nanoscale simulation of dislocations [17,18], various types of phase transformations (PTs) [19–21], cracks [22,23] and nanovoids [24–28]. Among the mentioned theories, the nonlocal elasticity theory, which is a prevalent approach to study the static and dynamic behavior of nanostructures, is the focus of this paper.…”

Section: Introductionmentioning

confidence: 99%

Free vibration analysis of nonlocal nanobeams: a comparison of the one-dimensional nonlocal integral Timoshenko beam theory with the two-dimensional nonlocal integral elasticity theory

Danesh

Javanbakht

2021

Mathematics and Mechanics of Solids

Self Cite

View full text Add to dashboard Cite

Beam theories such as the Timoshenko beam theory are in agreement with the elasticity theory. However, due to the different nonlocal averaging processes, they are expected to yield different results in their nonlocal forms. In the present work, the free vibration behavior of nonlocal nanobeams is studied using the nonlocal integral Timoshenko beam theory (NITBT) and two-dimensional nonlocal integral elasticity theory (2D-NIET) with different kernels and their results are compared. A new kernel, termed the compensated two-phase (CTP) kernel, is introduced, which entirely compensates for the boundary effects and does not suffer from the ill-posedness of previous kernels. Using the finite element method, the free vibration analysis is performed for different boundary conditions based on the first three natural frequencies. For both the NITBT and 2D-NIET with both the two-phase (TP) and CTP kernels, the nonlocal parameter has a softening effect on the natural frequencies for all the boundary conditions, without observing the paradoxical behaviors of the nonlocal differential theory. For both theories, the softening effect of the nonlocal parameter is more pronounced for the TP kernel compared to the CTP kernel. The sensitivity of the 2D-NIET to the nonlocal parameter is found to be higher than that of the NITBT. Also, the softening effects for different vibration modes are compared to each other for both theories and both kernels. The obtained results can be extended for various important beam problems with nonlocal effects and help obtain a better understanding of applicable nonlocal theories.

show abstract

“…A PFA was recently presented to study the nanovacancy evolution in the vicinity of an austenite–martensite interface [49]. The significant effects of nanovoids on phase transformations were studied by Javanbakht and colleagues [50-52]. It is acknowledged [53] that each material surface/interface that does not support elastic stresses is subjected to an inelastic biaxial tensile stress with the same magnitude of the surface energy γ .…”

Section: Introductionmentioning

confidence: 99%

Effect of a thermodynamically consistent interface stress on thermal-induced nanovoid evolution in NiAl

Ghaedi

Javanbakht

2021

Mathematics and Mechanics of Solids

Self Cite

View full text Add to dashboard Cite

In the present work, the effect of a thermodynamically consistent inelastic interface stress on nanovoid evolution in NiAl is studied. Such interface stress is introduced for the solid–gas interface of nanovoids within the concept of the phase field approach. The Cahn–Hilliard (CH) equation using the Helmholtz free energy describes the evolution of nanovoid concentration. The interface stress changes the total stress distribution and affects the elastic stress field. Thus, due to the significant effect of the elastic energy on nanovoid dynamics, it can indirectly affect nanovoid nucleation and growth. The highly nonlinear coupled CH and elasticity equations are solved using the finite element method and the COMSOL code. The coupling appears due to the presence of the nonlinear nanovoid inelastic strain in the total strain, the presence of the nonlinear inelastic interface stress in the stress tensor and the presence of elastic energy in the Helmholtz free energy. Several examples of thermal-induced nanovoid evolutions are presented to investigate the effect of the solid–gas interface stress. The obtained results show the significant effect of the interface stress on the total stress distribution, and consequently a different distribution of thermodynamic driving force which can affect the nanostructure evolution and the deformation. Mainly, the interface stress represents a promotive effect on nanovoid growth which results in a faster nanovoid growth and a larger nanovoid concentration and region.

show abstract

Nanovoid induced multivariant martensitic growth under negative pressure: Effect of misfit strain and temperature on PT threshold stress and phase evolution

Cited by 20 publications

References 94 publications

Interplay of Fracture and Martensite Transformation in Microstructures: A Coupled Problem

Interplay of Fracture and Martensite Transformation in Microstructures: A Coupled Problem

Free vibration analysis of nonlocal nanobeams: a comparison of the one-dimensional nonlocal integral Timoshenko beam theory with the two-dimensional nonlocal integral elasticity theory

Effect of a thermodynamically consistent interface stress on thermal-induced nanovoid evolution in NiAl

Contact Info

Product

Resources

About