Dislocation impacts on iron/precipitate interfaces under shear loading

Molecular dynamics simulations are performed to obtain a better understanding of the interactions of single dislocations and dislocation pile-ups with interfaces between iron and a precipitate. The material properties of the precipitate material and the iron-precipitate interaction are varied to understand the influence of interface structure, interface strength and precipitate stiffness on these interactions under shear loading. Our main findings are: (1) the interface adhesion is determined by a combination of the atomic interactions across the interface and the interface structure, (2) the interface structure is the key factor determining the dislocation accommodation capability of the interface: very strong semi-coherent interfaces do accommodate dislocations, while only very weak coherent interfaces are capable of doing this, and (3) a strong precipitate prevents slip transfer into the precipitate. Results of this study combined with those of a forthcoming study under tensile loading can be used to improve the description of interface decohesion in existing larger-scale models, such as discrete dislocation plasticity.

[1]  Herbert F. Wang,et al.  Single Crystal Elastic Constants and Calculated Aggregate Properties. A Handbook , 1971 .

[2]  C Gough,et al.  Introduction to Solid State Physics (6th edn) , 1986 .

[3]  Johnson.  Alloy models with the embedded-atom method. , 1989, Physical review. B, Condensed matter.

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

[5]  Acet,et al.  High-temperature moment-volume instability and anti-Invar of gamma -Fe. , 1994, Physical review. B, Condensed matter.

[6]  Peter M. Derlet,et al.  Grain-boundary sliding in nanocrystalline fcc metals , 2001 .

[7]  Richard G. Hoagland,et al.  On the strengthening effects of interfaces in multilayer fee metallic composites , 2002 .

[8]  Seungwu Han,et al.  Development of new interatomic potentials appropriate for crystalline and liquid iron , 2003 .

[9]  Graeme Ackland,et al.  Development of an interatomic potential for phosphorus impurities in α-iron , 2004 .

[10]  Y. Mishin,et al.  Interatomic Potentials for Metals , 2005 .

[11]  Akira Suzuki,et al.  Coupling grain boundary motion to shear deformation , 2006 .

[12]  D. McDowell,et al.  Structures and energies of Σ 3 asymmetric tilt grain boundaries in copper and aluminium , 2007 .

[13]  M. J. Luton,et al.  Crack-Tip Deformation Mechanisms in α-Fe and Binary Fe Alloys: An Atomistic Study on Single Crystals , 2007 .

[14]  A. Stukowski.  Visualization and analysis of atomistic simulation data with OVITO–the Open Visualization Tool , 2009 .

[15]  M. Marinica,et al.  Comparison of empirical interatomic potentials for iron applied to radiation damage studies , 2010 .

[16]  H. V. Swygenhoven,et al.  Coupled grain boundary motion in a nanocrystalline grain boundary network , 2011 .

[17]  Naveed Ahmed,et al.  Mechanisms of grain boundary softening and strain-rate sensitivity in deformation of ultrafine-grained metals at high temperatures , 2011 .

[18]  R. Hoagland,et al.  The influence of interface shear strength on the glide dislocation–interface interactions , 2011 .

[19]  J. Hirth,et al.  Slip transmission across fcc/bcc interfaces with varying interface shear strengths , 2012 .

[20]  A. Stukowski.  Structure identification methods for atomistic simulations of crystalline materials , 2012, 1202.5005.

[21]  Yong-Wei Zhang,et al.  Polycrystal deformation in a discrete dislocation dynamics framework , 2014 .

[22]  Masaki Tanaka,et al.  A multiscale approach for the deformation mechanism in pearlite microstructure: Atomistic study of the role of the heterointerface on ductility , 2014 .

[23]  Damage nucleation from repeated dislocation absorption at a grain boundary , 2014, 1405.3974.

[24]  Johannes J. Möller,et al.  Comparative study of embedded atom potentials for atomistic simulations of fracture in α-iron , 2014 .

[25]  Jian Wang.  Atomistic Simulations of Dislocation Pileup: Grain Boundaries Interaction , 2015 .