Investigations of pipe-diffusion-based dislocation climb by discrete dislocation dynamics

Gao, Yuan; Zhuang, Zhuo; Liu, Zhanli; You, Xiaoqing; Zhao, X.C.; Zhang, Zhi‐Hai

doi:10.1016/j.ijplas.2010.11.003

Cited by 65 publications

(24 citation statements)

References 48 publications

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“…In addition, dislocations can assist DPN through the formation of lath-like η by pipe diffusion paths that increase the overall diffusion rate [35]. Accordingly, Fig.…”

Section: Precipitation Evolution During Dynamic Compressionmentioning

confidence: 98%

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Afifi

Pereira

Wang

et al. 2017

Materials Science and Engineering: A

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An artificially aged Al-Zn-Mg alloy with a grain size of ~ 1.3 m was processed by equalchannel angular pressing (ECAP) and then subjected to dynamic compression at a strain rate of 4000 s -1 in the range from room temperature to 673 K. The results show the η phase is refined and a η phase is formed during the first pass of ECAP and after further processing 8 passes the GP zones are removed. An ultrafine-grained (UFG) structure with an average grain size of ~200 nm was obtained after 4 passes. It is shown that dynamic compressive deformation assists the precipitation process through precipitate coalescence and by changing the precipitate orientations.The dynamic compressive yield strengths and flow stresses decrease gradually to different degrees with increasing temperature except after ECAP processing for 4 passes where there is thermal stability up to 473 K. The ECAP processing significantly improves the strength of the alloy at elevated temperatures by comparison with the as-received material.

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“…In addition, dislocations can assist DPN through the formation of lath-like η by pipe diffusion paths that increase the overall diffusion rate [35]. Accordingly, Fig.…”

Section: Precipitation Evolution During Dynamic Compressionmentioning

confidence: 98%

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Afifi

Pereira

Wang

et al. 2017

Materials Science and Engineering: A

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“…Climb becomes relevant and often dominant at high temperatures or large vacancy concentrations, and is fundamental to such phenomena as creep, annealing, recrystallization, and irradiation damage. Elements of climb have been built into DDD [7][8][9][10] and PF [11,12] models, though this issue is still in many ways under development. Meaningful coarse-grained input parameters and their values, for example, which would ideally be extracted from microscopic simulations, are lacking.…”

Section: Introductionmentioning

confidence: 99%

Phase field crystal modeling as a unified atomistic approach to defect dynamics

et al. 2014

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Material properties controlled by evolving defect structures, such as mechanical response, often involve processes spanning many length and time scales which cannot be modeled using a single approach. We present a variety of new results that demonstrate the ability of phase field crystal (PFC) models to describe complex defect evolution phenomena on atomistic length scales and over long, diffusive time scales. Primary emphasis is given to the unification of conservative and nonconservative dislocation creation mechanisms in three-dimensional FCC and BCC materials. These include Frank-Read-type glide mechanisms involving closed dislocation loops or grain boundaries as well as Bardeen-Herring-type climb mechanisms involving precipitates, inclusions, and/or voids. Both source classes are naturally and simultaneously captured at the atomistic level by PFC descriptions, with arbitrarily complex defect configurations, types, and environments. An unexpected dipole-to-quadrupole source transformation is identified, as well as various new and complex geometrical features of loop nucleation via climb from spherical particles. Results for the strain required to nucleate a dislocation loop from such a particle are in agreement with analytic continuum theories. Other basic features of FCC and BCC dislocation structure and dynamics are also outlined, and initial results for dislocation-stacking fault tetrahedron interactions are presented. These findings together highlight various capabilities of the PFC approach as a coarse-grained atomistic tool for the study of three-dimensional crystal plasticity.

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“…Based on discrete dislocation dynamics simulations, Gao et al (2011) have incorporated pipe diffusion into a novel dislocation climb model.…”

Section: Thermal Stability Of Work Hardeningmentioning

confidence: 99%

Role of vacancies in work hardening and fatigue of TiAl alloys

Appel

Herrmann

Fischer

et al. 2013

International Journal of Plasticity

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The role of vacancies in work hardening and fatigue of TiAl alloys was investigated by mechanical testing and TEM examination of deformed samples. The evolution of the dislocation glide resistance during straining and after recovery was analyzed in terms of thermodynamic glide parameters. Strain path change tests with respect to temperature and recovery experiments were performed in order to characterize the thermal stability of the produced defect structures. The recovery of the deformation induced defect structure was observed by TEM in situ heating experiments. The recovery kinetics is described on the basis of a recently published simulation study of vacancy annihilation.

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Investigations of pipe-diffusion-based dislocation climb by discrete dislocation dynamics

Cited by 65 publications

References 48 publications

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Phase field crystal modeling as a unified atomistic approach to defect dynamics

Role of vacancies in work hardening and fatigue of TiAl alloys

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