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Molecular dynamics simulations of strengthening due to silver precipitates in copper matrix (Phys. Status Solidi B 5/2017)
Author(s) -
Hocker Stephen,
Rapp Dennis,
Schmauder Siegfried
Publication year - 2017
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201770225
Subject(s) - dislocation , copper , partial dislocations , materials science , precipitation , crystallography , molecular dynamics , glide plane , dissolution , condensed matter physics , slip (aerodynamics) , plane (geometry) , metallurgy , composite material , geometry , chemistry , thermodynamics , physics , computational chemistry , mathematics , meteorology
Precipitation is one of the most important strengthening mechanisms in alloys. To investigate its effect on dislocation motion in copper‐silver alloys, molecular dynamics simulations of the interaction between an edge dislocation and silver precipitates within the copper matrix have been employed by Hocker et al. (article no. 1600479 ). The influence of size, shape and coherency of a precipitate on this quantity is especially of interest. It is revealed that the circumvention mechanism of the passing dislocation at the precipitate/matrix interface is a result of specific reactions with misfit dislocations, often leading to sessile segments. In the cover's top row a characteristic case of cutting is shown: The trailing partial and two Shockley partials (green) of the interface react to alternating Lomer‐Cottrell and Hirth locks (grey and yellow), dissolving only after the leading partial has passed the precipitate. The presence of full dislocations (blue) at the interface facilitates Orowan circumvention (middle row). The trailing partial reacts with a full dislocation to a Frank partial (cyan) which cannot dissolve. Orowan circumvention is often accompanied by cross‐slip. Recombination of crossslipped segments can occur on a plane differing from the initial glide plane, leading to the formation of a double jog (bottom row).