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Structure and glide of Lomer and Lomer-Cottrell dislocations: Atomistic simulations for model concentrated alloy solid solutions

Journal Article · · Physical Review Materials
 [1];  [2];  [1]
  1. University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Materials Sciences Division
  2. University of California, Berkeley, CA (United States)
+ Show Author Affiliations

Lomer (L) and Lomer-Cottrell (LC) dislocations have long been considered to be central to work hardening in face-centered cubic (FCC) metals and alloys. These dislocations act as barriers of motion for other dislocations, and can serve as sites for twin nucleation. Recent focus on multicomponent concentrated FCC solid solution alloys has resulted in many reported observations of LC dislocations. While these and L dislocations are expected to have a role in the mechanical behavior of these alloys, little is understood about how variations in composition and associated fault energies change the response of these dislocations under stress. Here we present atomistic simulations of L and LC dislocations in a model Cu-Ni system and find that changes in composition and applied stress conditions result in a wide variety of responses, including changes in core configuration and (100) glide. The results are compared to and extend previous literature related to the nature of L/LC core structures and how they vary with respect to intrinsic materials properties and stress states. This study also provides insights into mechanisms such as twin nucleation that could have important implications for work hardening in FCC solid-solution alloys.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
2328540
Journal Information:
Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 10 Vol. 6; ISSN 2475-9953
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

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Figures / Tables (9)

FIG. 1(p. 5)figure FIG. 1
FIG. 2(p. 5)figure FIG. 2
FIG. 3(p. 7)figure FIG. 3
FIG. 4(p. 8)figure FIG. 4
FIG. 5(p. 9)figure FIG. 5
TABLE I(p. 9)table TABLE I
FIG. 6(p. 10)figure FIG. 6
TABLE II(p. 10)table TABLE II
FIG. 7(p. 11)figure FIG. 7

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Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
disclinations and dislocations
disordered alloys
solid solutions
twinning