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Mechanical behaviour of substitutional body centered cubic Fe-Ti solid solutions at temperatures between 77 and 900 K; Plasticite des solutions solides cubiques centrees substitutionnelles fer-titane aux temperatures comprises entre 77 et 900 K

Thesis/Dissertation:

Abstract

Plastic behavior of body-centered cubic, interstitial free, Fe-Ti substitutional solid solutions has been characterised. We obtained the following results: at temperatures below 500 K, the thermal component τ* of the critical resolved shear stress τ greatly increases. Solute additions (c >0.12 wt pc) results in: softening at temperatures below 200 K, hardening at temperatures between 200 and 500 K. Results are discussed on Peierls mechanism. At temperatures below 200 K, screw dislocation motion is controlled.by the nucleation of dislocation pairs over the Peierls'hill. Substitutional solute favoring this process gives account of the softening. At temperatures above 200 K, edge dislocation motion controls the strain. The observed hardening is explained by the interaction occurring between edge-dislocations and foreign atoms. At temperatures between 500 and 800 K, a Portevin-Le Chatelier effect is observed. This effect is characterised by two types of serrations. The activation energy of the PLC effect has been determined (E = 1,4 eV). The origin of this phenomenon is the diffusion of solute towards dislocation by a vacancy-mechanism. Two maxima have been observed on the (σ{sub ε} - T) curves. These are due to superposition of overstraining (hardening) and creation of dislocations (softening). The athermal component τ{sub μ} is  More>>
Authors:
Publication Date:
May 11, 1976
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-4817
Resource Relation:
Other Information: 163 refs.; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS website for current contact and E-mail addresses: http://www.iaea.org/inis/Contacts/; These Docteur Es Sciences Physiques
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; BCC LATTICES; DEFORMATION; DISLOCATIONS; ELASTICITY; HARDENING; INTERSTITIALS; IRON; IRON ALLOYS; MECHANICAL TESTS; PEIERLS-NABARRO FORCE; PLASTICITY; SOLUTES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TITANIUM; TITANIUM ADDITIONS
OSTI ID:
22263127
Research Organizations:
Universite de Paris-Sud Centre d'Orsay (France); Centre d'Etudes Nucleaires de Saclay, Institut National des Sciences et Techniques Nucleaires (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR1401917084354
Availability:
Available from INIS in electronic form
Submitting Site:
INIS
Size:
189 page(s)
Announcement Date:
Sep 16, 2014

Thesis/Dissertation:

Citation Formats

Dubots, Patrick. Mechanical behaviour of substitutional body centered cubic Fe-Ti solid solutions at temperatures between 77 and 900 K; Plasticite des solutions solides cubiques centrees substitutionnelles fer-titane aux temperatures comprises entre 77 et 900 K. France: N. p., 1976. Web.
Dubots, Patrick. Mechanical behaviour of substitutional body centered cubic Fe-Ti solid solutions at temperatures between 77 and 900 K; Plasticite des solutions solides cubiques centrees substitutionnelles fer-titane aux temperatures comprises entre 77 et 900 K. France.
Dubots, Patrick. 1976. "Mechanical behaviour of substitutional body centered cubic Fe-Ti solid solutions at temperatures between 77 and 900 K; Plasticite des solutions solides cubiques centrees substitutionnelles fer-titane aux temperatures comprises entre 77 et 900 K." France.
@misc{etde_22263127,
title = {Mechanical behaviour of substitutional body centered cubic Fe-Ti solid solutions at temperatures between 77 and 900 K; Plasticite des solutions solides cubiques centrees substitutionnelles fer-titane aux temperatures comprises entre 77 et 900 K}
author = {Dubots, Patrick}
abstractNote = {Plastic behavior of body-centered cubic, interstitial free, Fe-Ti substitutional solid solutions has been characterised. We obtained the following results: at temperatures below 500 K, the thermal component τ* of the critical resolved shear stress τ greatly increases. Solute additions (c >0.12 wt pc) results in: softening at temperatures below 200 K, hardening at temperatures between 200 and 500 K. Results are discussed on Peierls mechanism. At temperatures below 200 K, screw dislocation motion is controlled.by the nucleation of dislocation pairs over the Peierls'hill. Substitutional solute favoring this process gives account of the softening. At temperatures above 200 K, edge dislocation motion controls the strain. The observed hardening is explained by the interaction occurring between edge-dislocations and foreign atoms. At temperatures between 500 and 800 K, a Portevin-Le Chatelier effect is observed. This effect is characterised by two types of serrations. The activation energy of the PLC effect has been determined (E = 1,4 eV). The origin of this phenomenon is the diffusion of solute towards dislocation by a vacancy-mechanism. Two maxima have been observed on the (σ{sub ε} - T) curves. These are due to superposition of overstraining (hardening) and creation of dislocations (softening). The athermal component τ{sub μ} is increased by titanium additions. This hardening has been explained by modulus and size effects. (author) [French] La caracterisation des mecanismes controlant la deformation plastique des solutions solides cubiques centrees substitutionnelles fer-titane, libres d'interstitiels pour les teneurs en solute superieures a 0,12pc pds, a donne les resultats suivants: aux temperatures inferieures a 500 K, la composante thermique τ* de la contrainte critique de cisaillement resolue τ augmente fortement. L'introduction du solute se traduit (pour c>0,12 pc pds): par un adoucissement pour θ < 200 K; par un durcissement pour 200 K< θ < 500 K. Le mecanisme de Peierls rend compte de ces resultats. Pour θ < 200 K, le deplacement des dislocations vis est controle par la nucleation de decrochements surmontant la colline de Peierls. Ce processus est favorise par la presence d'atomes de titane en substitution. Pour θ > 200 K, la deformation est controlee par le deplacement des dislocations coins. L'interaction entre celles-ci et les substitutionnels explique le durcissement observe aux temperatures comprises entre 500 et 800 K, il existe un effet Portevin-Le Chatelier (PLC) caracterise par deux types de hachures. L'energie d'activation du phenomene (evaluee a 1,4 eV) a ete reliee a un mecanisme de diffusion lacunaire du titane vers les dislocations. Cet effet PLC se traduit par l'existence de deux maxima sur les courbes σ{sub ε} = f (T), analyses en termes de surconsolidation attenuee par l'existence des hachures. L'addition du titane provoque une augmentation de la composante thermique τ{sub μ}. Ce durcissement a ete interprete en termes d'effets de taille et de module. (auteur)}
place = {France}
year = {1976}
month = {May}
}