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Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase

Conference:

Abstract

A method is developed for studying with radioisotopes the behaviour of grain boundaries in the process of plastic deformation and later recrystallization. It is shown that iron recrystallization at relatively low (15%) and high (50-70%) degrees of deformation does not lead to any essential change in the location of the basic metal atoms situated at the boundary of the initial grains. If the metal structure changes considerably after recrystallization and also after polymorphous {alpha} {r_reversible} {gamma} transformation, the boundary atoms of the initial grains are but slightly displaced. In the same way, impurity atoms (radioactive carbon) situated at the boundaries of the initial grain do not migrate across the boundaries of the new grains of recrystallized metal. Plastic deformation, however, is accompanied by considerable migration of the atoms situated at the grain boundary. The data obtained show that the migration of grain boundaries during recrystallization and subsequent grain-growth are associated with some specific mechanism differing from ordinary diffusion. It is shown that structural changes occurring in alloys at high temperatures can change the rate of self-diffusion and hetero-diffusion processes. A study of the diffusion processes in titanium and its alloys in connection with the polymorphous state shows that the rate  More>>
Publication Date:
Jan 15, 1962
Product Type:
Conference
Resource Relation:
Conference: Conference on the Use of Radioisotopes in the Physical Sciences and Industry, Copenhagen (Denmark), 6-17 Sep 1960; Other Information: 12 figs, 1 tab., 9 refs; Related Information: In: Radioisotopes in the Physical Sciences and Industry. Proceedings of the Conference on the Use of Radioisotopes in the Physical Sciences and Industry. V. 1| 556 p.
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; ALLOYS; ATOMS; CARBON; CRYSTALS; DEFORMATION; GRAIN BOUNDARIES; GRAIN GROWTH; IMPURITIES; IRON; MELTING POINTS; PHASE TRANSFORMATIONS; PLASTICITY; RADIOISOTOPES; RECRYSTALLIZATION; SELF-DIFFUSION; TITANIUM; TRANSFORMATIONS
OSTI ID:
22025626
Research Organizations:
International Atomic Energy Agency, Vienna (Austria); United Nations Educational, Scientific and Cultural Organization, Paris (France)
Country of Origin:
IAEA
Language:
Russian
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA12N1605112919
Submitting Site:
INIS
Size:
page(s) 193-206
Announcement Date:
Jan 16, 2013

Conference:

Citation Formats

Bokshtejn, S Z, Gubareva, M A, Kishkin, S T, and Moroz, L M. Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase. IAEA: N. p., 1962. Web.
Bokshtejn, S Z, Gubareva, M A, Kishkin, S T, & Moroz, L M. Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase. IAEA.
Bokshtejn, S Z, Gubareva, M A, Kishkin, S T, and Moroz, L M. 1962. "Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase." IAEA.
@misc{etde_22025626,
title = {Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase}
author = {Bokshtejn, S Z, Gubareva, M A, Kishkin, S T, and Moroz, L M}
abstractNote = {A method is developed for studying with radioisotopes the behaviour of grain boundaries in the process of plastic deformation and later recrystallization. It is shown that iron recrystallization at relatively low (15%) and high (50-70%) degrees of deformation does not lead to any essential change in the location of the basic metal atoms situated at the boundary of the initial grains. If the metal structure changes considerably after recrystallization and also after polymorphous {alpha} {r_reversible} {gamma} transformation, the boundary atoms of the initial grains are but slightly displaced. In the same way, impurity atoms (radioactive carbon) situated at the boundaries of the initial grain do not migrate across the boundaries of the new grains of recrystallized metal. Plastic deformation, however, is accompanied by considerable migration of the atoms situated at the grain boundary. The data obtained show that the migration of grain boundaries during recrystallization and subsequent grain-growth are associated with some specific mechanism differing from ordinary diffusion. It is shown that structural changes occurring in alloys at high temperatures can change the rate of self-diffusion and hetero-diffusion processes. A study of the diffusion processes in titanium and its alloys in connection with the polymorphous state shows that the rate of the process in different titanium-crystal variations varies greatly. This eliminates the previous discrepancy between the high melting-point of titanium and the relatively low activation energy of the diffusion process in titanium. (author) [French] Les auteurs ont mis au point une methode qui permet d'etudier, a l'aide des radioisotopes, le comportement des joints de grains au cours de la deformation plastique et de la recristallisation consecutive. Ils ont demontre que la recristallisation du fer, a des degres de deformation relativement faibles (15%) et relativement eleves (50-70%), n'entraine pas de modification importante dans l'emplacement des atomes du metal de base qui se trouve aux joints des grains initiaux. En cas de modification importante de la structure du metal apres recristallisation, et aussi apres transformation polymorphique {alpha} {r_reversible} {gamma}, les atomes des joints des grains initiaux ne subissent qu'un tres faible deplacement. D'une facon analogue, les atomes de l'element d'addition (carbone radioactif) places aux joints des grains initiaux ne traversent pas les joints des nouveaux grains du metal recristallise. En revanche, la deformation plastique s'accompagne d'un deplacement considerable des atomes places aux joints de grains. Les donnees obtenues par les auteurs montrent que la traversee des joints de grains pendant la recristallisation et la croissance consecutive des grains, est liee a un mecanisme specifique qui differe de la diffusion ordinaire. Les auteurs montrent que les transformations structurales qui se produisent dans les alliages a des temperatures elevees peuvent modifier la vitesse des processus d'autodiffusion et d'heterodiffusion. A la suite d'une etude des processus de diffusion dans le titane et ses alliages selon l'etat polymorphique, les auteurs ont etabli que la vitesse du processus est tres differente pour les diverses varietes allotropiques du titane. Ainsi disparait la contradiction qui existait entre le point de fusion eleve du titane et l'energie d'activation relativement faible du processus de diffusion dans le titane. (author) [Spanish] Los autores han elaborado un metodo para investigar con ayuda de radioisotopos el comportamiento de los limites de los granulos durante la deformacion plastica y la recristalizacion subsiguiente. Han demostrado que la recristalizacion del hierro, cuando las deformaciones son de grado relativamente pequeno (15 por ciento) o elevado (50-70 por ciento) no afecta sensiblemente la posicion de los atomos del metal de base que se encuentran en los limites de los granulos iniciales. Cuando la estructura del metal sufre modificaciones importantes despues de la recristalizacion, asi como despues de la transformacion polimorfica {alpha} {r_reversible} {gamma}, los atomos situados en los limites de los granulos iniciales no experimentan desplazamientos considerables. De manera analoga, los atomos de un aditivo (carbono radiactivo) situados en los limites de los granulos iniciales no migran a traves de los limites de los nuevos granulos del metal recristalizado. En cambio, la deformacion plastica va acompanada de migraciones considerables de los atomos situados en los limites de los granulos. Los datos obtenidos demuestran que la migracion de los limites de los granulos durante la recristalizacion y subsiguiente formacion de los granulos esta relacionada con un mecanismo especifico distinto del habitual mecanismo de difusion. Los autores han demostrado que las transformaciones estructurales que ocurren en las aleaciones a temperaturas elevadas pueden modificar la velocidad de los proceseos de autodifusion y heterodifusion. Basandose en el estudio de los procesos de difusion en el titanio y sus aleaciones en relacion con el estado polimorfico, los autores han comprobado que la velocidad de los procesos difiere notablemente en las distintas variedades cristalinas del titanio. Con ello desaparece la contradicion que existia entre el elevado punto de fusion del titanio y la energia de activacion del proceso de difusion en este elemente, que es relativamente baja. (author) [Russian] Razrabotana metodika, pozvolyayushchaya s pomoshch'yu radioaktivnykh izotopov issledovat' povedenie granits zeren v protsesse plasticheskoj deformatsii i posleduyushchej rekristallizatsii. Pokazano, chto rekristallizatsiya zheleza pri sravnitel'no malykh (15%) i bol'shikh (50-70%) stepenyakh deformatsii ne privodit k sushchestvennomu izmeneniyu mestopolozheniya atomov osnovnogo metalla, nakhodyashchikhsya na granitse iskhodnykh zeren. Pri znachitel'nom izmenenii struktury metalla posle rekristallizatsii, a takzhe posle polimorfnogo {alpha} {r_reversible} {gamma} prevrascheniya, atomy granits iskhodnykh zeren ne smeshchayutsya na znachitel'nye rasstoyaniya. Analogichno, atomy primesi (radioaktivnyj uglerod), raspolozhennye na granitsakh iskhodnogo zerna, ne perekhodyat na granitsy novykh zeren rekristallizovannogo metalla. V otlichie ot ehtogo plasticheskaya deformatsiya soprovozhdaetsya znachitel'nym peremeshcheniem atomov, raspolozhennykh na granitse zerna. Poluchennye dannye pokazyvayut, chto peremeshchenie granits zeren pri rekristallizatsii i pri posleduyushchem roste zeren svyazano s nekotorym spetsificheskim mekhanizmom, otlichnym ot obychnogo diffuzionnogo. Pokazano, chto strukturnye izmeneniya, protekayushchie v splavakh pri vysokikh temperaturakh, mogut izmenyat' skorost' protsessov samodiffuzii i geterodiffuzii. V rezul'tate issledovaniya diffuzionnykh protsessov v titane i ego splavakh v zavisimosti ot polimorfnogo sostoyaniya ustanovleno, chto skorost' protsessa v razlichnykh kristallicheskikh modifikatsiyakh titana sil'no otlichaetsya. EHtim snimaetsya sushchestvovavshee protivorechie mezhdu vysokoj temperaturoj plavleniya titana i otnositel'no nizkoj ehnergiej aktivatsii protsessa diffuzii v titane. (author)}
place = {IAEA}
year = {1962}
month = {Jan}
}