Molecular dynamics simulations of the coupled effects of strain and temperature on displacement cascades in α-zirconium

Abstract In this article, we conducted molecular dynamics simulations to investigate the effect of applied strain and temperature on irradiation-induced damage in alpha-zirconium. Cascade simulations were performed with primary knock-on atom energies ranging between 1 and 20 KeV, hydrostatic and uniaxial strain values ranging from −2% (compression) to 2% (tensile), and temperatures ranging from 100 to 1000 K. Results demonstrated that the number of defects increased when the displacement cascade proceeded under tensile uniaxial hydrostatic strain. In contrast, compressive strain states tended to decrease the defect production rate as compared with the reference no-strain condition. The proportions of vacancy and interstitial clustering increased by approximately 45% and 55% and 25% and 32% for 2% hydrostatic and uniaxial strain systems, respectively, as compared with the unstrained system, whereas both strain fields resulted in a 15–30% decrease in vacancy and interstitial clustering under compressive conditions. Tensile strains, specifically hydrostatic strain, tended to produce larger sized vacancy and interstitial clusters, whereas compressive strain systems did not significantly affect the size of defect clusters as compared with the reference no-strain condition. The influence of the strain system on radiation damage became more significant at lower temperatures because of less annealing than in higher temperature systems.

[1]  Steve Plimpton,et al.  Fast parallel algorithms for short-range molecular dynamics , 1993 .

[2]  C. K. Chow,et al.  Deformation of zirconium irradiated by 4.4 MeV protons at 347 K , 2004 .

[3]  J. Kai,et al.  The microstructural evolution of zircaloy-4 subjected to proton irradiation , 1990 .

[4]  Cascade Overlap in hcp Zirconium: Defect Accumulation and Microstructure Evolution with Radiation using Molecular Dynamics Simulations , 2013 .

[5]  M. Daymond,et al.  Evaluating zirconium–zirconium hydride interfacial strains by nano-beam electron diffraction , 2013 .

[6]  B. Eyre,et al.  The Growth and Stability of Voids in Irradiated Metals , 1970 .

[7]  M. Daymond,et al.  In situ study of defect accumulation in zirconium under heavy ion irradiation , 2013 .

[8]  A. Legris,et al.  Ab initio atomic-scale determination of point-defect structure in hcp zirconium , 2005 .

[9]  L. M. Howe,et al.  A molecular dynamics study of high-energy displacement cascades in α-zirconium , 1998 .

[10]  G. Nandipati,et al.  Displacement cascades and defects annealing in tungsten, Part I: Defect database from molecular dynamics simulations , 2014, 1404.6490.

[11]  Roger E. Stoller,et al.  MD description of damage production in displacement cascades in copper and α-iron , 2003 .

[12]  James F. Ziegler,et al.  Refined universal potentials in atomic collisions , 1982 .

[13]  G. Ackland,et al.  Development of an interatomic potential for the simulation of phase transformations in zirconium , 2007 .

[14]  Fei Gao,et al.  Temperature-dependence of defect creation and clustering by displacement cascades in α-zirconium , 2001 .

[15]  Niels Grønbech-Jensen,et al.  Effect of strain and temperature on the threshold displacement energy in body-centered cubic iron , 2016, 1604.01791.

[16]  H. Khater,et al.  Dislocation core structure and dynamics in two atomic models of α-zirconium , 2010 .

[17]  M. Daymond,et al.  Molecular dynamics simulations of irradiation cascades in alpha-zirconium under macroscopic strain , 2013 .

[18]  D. Bacon,et al.  Defect production due to displacement cascades in metals as revealed by computer simulation , 1997 .

[19]  E. Bitzek,et al.  Influence of intrinsic strain on irradiation induced damage: the role of threshold displacement and surface binding energies , 2016 .

[20]  A. Serra,et al.  On the structure and mobility of point defect clusters in alpha-zirconium: a comparison for two interatomic potential models , 2011 .

[21]  G. Ackland,et al.  Defect, surface and displacement-threshold properties of α-zirconium simulated with a many-body potential , 1995 .

[22]  D. Bacon,et al.  Identification and morphology of point defect clusters created in displacement cascades in α-zirconium , 2006 .

[23]  W. Petry,et al.  Heavy ion irradiation induced dislocation loops in AREVA’s M5® alloy , 2012 .

[24]  Gary S. Was,et al.  Fundamentals of Radiation Materials Science: Metals and Alloys , 2007 .

[25]  C. Domain.  Ab initio modelling of defect properties with substitutional and interstitials elements in steels and Zr alloys , 2006 .

[26]  A. Bakai,et al.  Atomistic simulation of primary damages in Fe, Ni and Zr , 2013 .