Journal ArticleDOI
The effect of dislocation drag on the stress-strain behavior of F.C.C. metals
TLDR
In this article, it was shown that the strong upturn reported for the flow stress of copper is not caused by dislocation drag, and the likely explanation is an enhanced rate of dislocation generation.Abstract:
The introduction of viscous drag into a simple thermally activated dislocation model for the low temperature plastic deformation of f.c.c. metals leads to some surprising predictions about their stress-strain behavior. One effect of dislocation drag is to produce a region of tensile instability at small strains for any strain rate. At sufficiently high strain rates there is no region of tensile stability. However, computation of a decreased strain for tensile instability at strain rates greater than 103 s−1, in opposition to experimental measurements, provides evidence that the strong upturn reported for the flow stress of copper is not caused by dislocation drag. The likely explanation is an enhanced rate of dislocation generation.read more
Citations
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Mechanical properties of high-entropy alloys with emphasis on face-centered cubic alloys
TL;DR: In this paper, the authors review the principal mechanical properties of multi-principal element alloys with emphasis on the face-centered cubic systems, such as the CrCoNi-based alloys, and suggest their favorable mechanical properties and ease of processing by conventional means suggest extensive utilization in many future structural applications.
Journal ArticleDOI
High strain rate properties of metals and alloys
TL;DR: In this article, the high strain rate dependence of the flow stress of metals and alloys is described from a dislocation mechanics viewpoint over a range beginning from conventional tension/compression testing through split Hopkinson pressure bar (SHPB) measurements to Charpy pendulum and Taylor solid cylinder impact tests and shock loading or isentropic compression experiment (ICE) results.
Journal ArticleDOI
Impact properties and microstructure evolution of 304L stainless steel
Woei-Shyan Lee,Chi Feng Lin +1 more
TL;DR: In this article, the impact properties and microstructure evolution of 304L stainless steel have been studied systematically by means of a split Hopkinson bar and TEM metallographic techniques.
Journal ArticleDOI
Thermomechanical response of AL-6XN stainless steel over a wide range of strain rates and temperatures
TL;DR: In this article, a physically based model is developed for the deformation behavior of AL-6XN stainless steel, including the effect of viscous drag on the motion of dislocations, but excluding the dynamic strain aging effects.
References
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Journal ArticleDOI
Dislocation-mechanics-based constitutive relations for material dynamics calculations
TL;DR: An improved description of copper and ironcylinder impact (Taylor) test results has been obtained through the use of dislocation-mechanics-based constitutive relations in the Lagrangian material dynamics computer program EPIC•2.
Journal ArticleDOI
A constitutive description of the deformation of copper based on the use of the mechanical threshold stress as an internal state variable
P.S. Follansbee,U.F. Kocks +1 more
TL;DR: In this article, the axisymmetric deformation behavior of 0.9999 Cu is investigated at strain rates from 10−4 to 104 s−1, and it is shown that the athermal dislocation accumulation rate, or Stage II hardening rate, becomes a strong function of strain rate.
Journal ArticleDOI
An experimental study of the mobility of edge dislocations in pure copper single crystals
K. M. Jassby,Thad Vreeland +1 more
TL;DR: In this article, the authors measured the velocity of selectively-introduced edge dislocations in 99.999 percent pure copper crystals and measured the stress at temperatures from 66°K to 373°K by means of a torsion-inducing technique.
Journal ArticleDOI
Work hardening and rate sensitivity material coefficients for OFHC Cu and 99.99% A1
N. Christodoulou,J.J. Jonas +1 more
TL;DR: In this article, large strain tensile tests were carried out on OFHC Cu and 99.9% A1 with the aim of determining the first and second order work hardening and rate sensitivity coefficients.
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Dislocation-mechanics-based constitutive relations for material dynamics calculations
A constitutive description of the deformation of copper based on the use of the mechanical threshold stress as an internal state variable
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