Author:

Keywords:

Science & Technology, Technology, Materials Science, Multidisciplinary, Metallurgy & Metallurgical Engineering, Materials Science, Dislocation dynamics, Strength, Low-angle grain boundary, Hexagonal dislocation network, Dislocation processes, RANGE INTERNAL-STRESSES, IRON SINGLE-CRYSTALS, HIGH-TEMPERATURE CREEP, ALPHA-IRON, INTERMEDIATE TEMPERATURES, PLASTIC-DEFORMATION, EDGE DISLOCATION, CELL STRUCTURES, FCC METALS, MECHANISMS, 0204 Condensed Matter Physics, 0912 Materials Engineering, 0913 Mechanical Engineering, Materials, 4016 Materials engineering, 4017 Mechanical engineering, 5104 Condensed matter physics

Abstract:

The interaction of dislocations with low-angle grain boundaries (LAGBs) is considered one important contribution to the mechanical strength of metals. Although LAGBs have been frequently observed in metals, little is known about how they interact with free dislocations that mainly carry the plastic deformation. Using discrete dislocation dynamics simulations, we are able to quantify the resistance of a LAGB - idealized as three sets of dislocations that form a hexagonal dislocation network - against lattice dislocation penetration, and examine the associated dislocation processes. Our results reveal that such a coherent internal boundary can massively obstruct and even terminate dislocation transmission and thus make a substantial contribution to material strength. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.