Irradiation Hardening and Embrittlement in Body-Centered Cubic Transition Metals

2009 ◽  
pp. 69-69-17 ◽  
Author(s):  
A. S. Wronski ◽  
G. A. Sargent ◽  
A. A. Johnson
Keyword(s):  
Transition Metals ◽  
Body Centered Cubic ◽  
Irradiation Hardening

Study of the Mechanical Behavior of BCC Transition Metals Using Bond-Order Potentials

1999 ◽  
Vol 578 ◽  
Author(s):  
M. Mrovec ◽  
V. Vitek ◽  
D. Nguyen-Manh ◽  
D. G. Pettifor ◽  
L. G. Wang ◽  
...  
Keyword(s):  
Transition Metals ◽  
Bond Order ◽  
Tight Binding ◽  
Dislocation Core ◽  
Body Centered Cubic ◽  
Alternative Structures ◽  
The Core ◽  
Deformation Properties ◽  
Directional Bonding ◽  
Bond Order Potentials

AbstractDeformation properties of body-centered-cubic transition metals are controlled by the core structure of screw dislocations and their studies involve extensive computer simulations. In this paper we present the recently constructed bond-order potentials (BOP) that are based on the realspace parametrized tight-binding method. In order to examine the applicability of the potentials we have evaluated the energy differences of alternative structures, investigated several transformation paths leading to large distortions and calculated phonon dispersions. Using these potentials we have calculated γ-surfaces that relate to the dislocation core structures and discuss then the importance of directional bonding in studies of dislocations in transition metals.

Parameter Representation of Low-Temperature Yield Behavior of Body-Centered Cubic Transition Metals

1966 ◽  
Vol 88 (2) ◽  
pp. 518-524 ◽  
Author(s):  
P. E. Bennett ◽  
G. M. Sinclair
Keyword(s):  
Low Temperature ◽  
Transition Metals ◽  
Brittle Fracture ◽  
Yield Strength ◽  
Strain Rate ◽  
Body Centered Cubic ◽  
Yield Behavior ◽  
Bcc Metals ◽  
State Of Stress ◽  
Iron Chromium

In the low-temperature range, the engineering yield strength of polycrystalline bcc metals can change by a factor of 10 or more with serious consequences appearing in the form of catastrophic brittle fracture. Engineering variables known to have an important effect on the yield behavior are state of stress, temperature, loading or strain rate, composition, and microstructure. For iron, chromium, molybdenum, and tungsten, it is shown that yield behavior can be represented by a single-valued relation between two dimensionless parameters.

Comments on stage III annealing in group VA body-centered cubic transition metals

1973 ◽  
Vol 7 (1) ◽  
pp. 7-14 ◽  
Author(s):  
M.S. Wechsler ◽  
J.M. Williams ◽  
J.T. Stanley
Keyword(s):  
Transition Metals ◽  
Stage Iii ◽  
Body Centered Cubic

scholarly journals Theoretical investigation of the 70.5∘ mixed dislocations in body-centered cubic transition metals

2021 ◽  
pp. 117154
Author(s):  
Lorenz Romaner ◽  
Tapaswani Pradhan ◽  
Anastasiia Kholtobina ◽  
Ralf Drautz ◽  
Matous Mrovec
Keyword(s):  
Transition Metals ◽  
Theoretical Investigation ◽  
Body Centered Cubic

scholarly journals Alloying-Driven Phase Stability in Group-VB Transition Metals under Compression

2011 ◽  
Vol 1369 ◽  
Author(s):  
Alexander Landa ◽  
Per Söderlind
Keyword(s):  
Transition Metals ◽  
Band Structure ◽  
Phase Stability ◽  
The Body ◽  
Cubic Phase ◽  
Body Centered Cubic ◽  
Transition Series ◽  
Transverse Acoustic ◽  
Band Structure Energy ◽  
Bcc Phase

ABSTRACTThe change in phase stability of Group-VB (V, Nb, and Ta) transition metals due to pressure and alloying is explored by means of first-principles electronic-structure calculations. It is shown that under compression stabilization or destabilization of the ground-state body-centered cubic (bcc) phase of the metal is mainly dictated by the band-structure energy that correlates well with the position of the Kohn anomaly in the transverse acoustic phonon mode. The predicted position of the Kohn anomaly in V, Nb, and Ta is found to be in a good agreement with data from the inelastic x-ray or neutron scattering measurements. In the case of alloying the change in phase stability is defined by the interplay between the band-structure and Madelung energies. We show that band-structure effects determine phase stability when a particular Group-VB metal is alloyed with its nearest neighbors within the same d-transition series: the neighbor with less and more d electrons destabilize and stabilize the bcc phase, respectively. When V is alloyed with neighbors of a higher (4d- or 5d-) transition series, both electrostatic Madelung and band-structure energies stabilize the body-centered-cubic phase. The opposite effect (destabilization) happens when Nb or Ta is alloyed with neighbors of the 3d-transition series.

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