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dislocation density

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Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005432
EISBN: 978-1-62708-196-2
..., distributing nuclei of recrystallized grains, growing the recrystallized grains, and updating the dislocation density. The article concludes with information on the developments in CA simulations. cellular automaton model static recrystallization dynamic recrystallization microstructure dislocation...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005403
EISBN: 978-1-62708-196-2
...-temperature deformation during further heat treatment. In the initial fully annealed state ( Fig. 1a ), the dislocation density of the material is very low (ρ ≈ 0.01 μm/μm 3 ). Strain hardening makes it grow to 10 4 μm/μm 3 ( Fig. 1b ). Since it was formerly believed that metals lost their crystalline...
Book Chapter

By Sammy Tin
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005404
EISBN: 978-1-62708-196-2
... of a number of dynamic microstructural variables, such as material composition, grain size, dislocation density, precipitate size, and morphology, that evolve during the course of deformation. Thus, the time-dependent behavior of the structure parameter is also dependent on the stress, temperature...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005459
EISBN: 978-1-62708-196-2
... state variable such as a grain number, crystallographic orientation, or dislocation density/level of stored work. Areas formed by cells with an identical grain number or similar state variable(s) define the grains. A set of rules defines the conditions by which cells may switch, that is, may change...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005413
EISBN: 978-1-62708-196-2
... is based on the assumption that dislocation accumulation is governed by only one state variable, namely, the total dislocation density. This leads to a differential equation, a so-called state function, for dislocation accumulation in which history variables such as strain and time only appear...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004027
EISBN: 978-1-62708-185-6
... variables, which is important not only for the working forces but also for the product properties. During a deformation pass, the flow stress changes with strain as a result of athermal work-hardening processes that increase the dislocation density, and opposing thermally activated softening processes...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0009002
EISBN: 978-1-62708-185-6
... content. However, the dislocation density does not increase without limit because of the occurrence of dynamic recovery and dynamic recrystallization. In high stacking-fault-energy (SFE) metals (e.g., aluminum and its alloys, iron in the ferrite phase field, titanium alloys in the beta phase field...
Series: ASM Handbook
Volume: 4E
Publisher: ASM International
Published: 01 June 2016
DOI: 10.31399/asm.hb.v04e.a0006255
EISBN: 978-1-62708-169-6
... to the proper processing of these materials. As refractory metals are worked, the grains become deformed and the dislocation density increases, increasing their strength. During processing, recovery anneals reduce the dislocation density while avoiding recrystallization and grain growth to reduce...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004019
EISBN: 978-1-62708-185-6
..., edge dislocation dipoles, and cusps on dislocation lines. Thin-foil TEM specimen prepared parallel to the rolling plane. Original magnification 62,000× Fig. 4 Fe-3Si single crystal, cold rolled 20% in the (111)[11 2 ] orientation showing increased density of dislocations and clusters of short...
Series: ASM Handbook
Volume: 4E
Publisher: ASM International
Published: 01 June 2016
DOI: 10.31399/asm.hb.v04e.a0006285
EISBN: 978-1-62708-169-6
... is designated “O.” (This temper was designated “T2” prior to 1975.) Recovery requires sufficient dislocation densities to be either annihilated or rearranged by interaction in their own stress fields. The dislocation climbing process involved is initiated by excess vacancies that are generated...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004020
EISBN: 978-1-62708-185-6
... against barriers, which requires increased stress for their motion. As the stress rises, new dislocations of the appropriate sign are activated and those of the opposite sign are annihilated. Thus, the density of mobile dislocations increases during uploading without their release from the barriers...
Series: ASM Handbook
Volume: 14B
Publisher: ASM International
Published: 01 January 2006
DOI: 10.31399/asm.hb.v14b.a0005183
EISBN: 978-1-62708-186-3
... and those of the opposite sign are annihilated. Thus, the density of mobile dislocations increases during uploading without their release from the barriers. Conversely, their density is decreased due to annihilation and dislocation runback during unloading. Upon reverse reloading, there is again a rise...
Series: ASM Handbook
Volume: 9
Publisher: ASM International
Published: 01 December 2004
DOI: 10.31399/asm.hb.v09.a0003784
EISBN: 978-1-62708-177-1
... prepared with very low dislocation densities, but because pure metal crystals are very soft, this requires great care to reduce thermal and mechanical stresses during growth and subsequent handling. Most metal single crystals have dislocation densities of about 10 6 to 10 7 per square centimeter...
Series: ASM Handbook
Volume: 20
Publisher: ASM International
Published: 01 January 1997
DOI: 10.31399/asm.hb.v20.a0002460
EISBN: 978-1-62708-194-8
..., but the extent to which they exist varies among the material classes. The quantity of dislocations (the dislocation density ) can be expressed in terms of their number per unit area. With reference to Fig. 11 , for example, the dislocation density would be the number of dislocations emerging from a surface...
Book Chapter

By G.R. Speich
Series: ASM Handbook
Volume: 1
Publisher: ASM International
Published: 01 January 1990
DOI: 10.31399/asm.hb.v01.a0001026
EISBN: 978-1-62708-161-0
...) and a dual-phase steel (with a yield strength of 550 MPa, or 80 ksi). Source: Ref 4 Fig. 8 Transmission electron micrograph of martensite substructure and high dislocation density in ferrite in a 0.04C-1.5Mn steel intercritically annealed at 726 °C (1340 °F) and rapidly cooled. Source: Ref 9...
Series: ASM Handbook
Volume: 2A
Publisher: ASM International
Published: 30 November 2018
DOI: 10.31399/asm.hb.v02a.a0006487
EISBN: 978-1-62708-207-5
... partial annealing; in the latter, some recrystallization may occur, whereas in the former, recovery only is used to achieve the required properties, accomplished by substructural changes in dislocation density and rearrangement into cellular patterns (polygonization). Bendability and formability...
Series: ASM Handbook
Volume: 19
Publisher: ASM International
Published: 01 January 1996
DOI: 10.31399/asm.hb.v19.a0002355
EISBN: 978-1-62708-193-1
... of dislocation structures produced during cycling. Besides the difference in the quantity of the PSBs in wavy-slip materials, there is a minor difference between surface and interior dislocation structures in both single crystals and polycrystals: the dislocation density in the volumes near the surface...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005455
EISBN: 978-1-62708-196-2
... pertinent to structural materials, namely, solid-solution strengthening, age/precipitation hardening, dispersion strengthening, grain size reduction, strengthening from cold work, and strengthening from interfaces. It explains the application of predictive models in the atomistic modeling of dislocation...
Series: ASM Handbook
Volume: 4D
Publisher: ASM International
Published: 01 October 2014
DOI: 10.31399/asm.hb.v04d.a0005962
EISBN: 978-1-62708-168-9
.... , Dislocations , Vol 3 , 1st English ed. , Pergamon Press , Oxford, U.K. , 1964 116. Russell K.C. and Brown L. , A Dispersion Strengthening Model Based on Differing Elastic Moduli Applied to the Iron-Copper System , Acta Metall. , Vol 20 , 1972 , p 969 – 974 10.1016/0001-6160(72...
Series: ASM Handbook
Volume: 22A
Publisher: ASM International
Published: 01 December 2009
DOI: 10.31399/asm.hb.v22a.a0005408
EISBN: 978-1-62708-196-2
... of a breakdown and three-stand tandem mill, has been simulated ( Fig. 9a ) using the coupled models RoseRoll, StrucSim, 4IVM, RoseTem, and RoseStat ( Ref 17 ). The results of such integrated simulation models can be used for a quantitative description of the dislocation densities ( Fig. 9b...