Relationship between Formation of Geometrically Necessary Dislocations and Local Strain Hardening of Slip Systems in Symmetric Type Bicrystals under Tensile Loading

The selection of twin variants has a great influence on deformation texture and mechanical property in hcp metals where slip systems are limited and twinning types are abundant during deformation. Local strain accommodations among twin variants are considered to shed light on variant selection rules in Ti and Mg alloys. Five kinds of strain accommodations are discussed in terms of different regions that are affected by the twinning shear of primary twin. These regions contain (I) the whole sample, (II) neighboring grain, (III) adjacent primary twin in neighboring grain, (IV) adjoining primary twin within the same parent grain, and (V) multi-generation of twinning inside the primary twin. For a potentially active variant, its operation needs not only relatively higher resolved shear stress but also easily accommodated strain by immediate vicinity. Many of the non-Schmid behaviors could be elucidated by local strain accommodations that variants with relatively higher SFs hard to be accommodated are absent, while those with relatively lower SFs but could be easily accommodated are present.

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The operative slip systems and strain hardening behaviour of β′-AgMg single crystals

phys stat sol (a) ◽

10.1002/pssa.2210140222 ◽

1972 ◽

Vol 14 (2) ◽

pp. 545-559 ◽

Cited By ~ 8

Author(s):

M. O. Aboelfotoh

Keyword(s):

Strain Hardening ◽

Single Crystals ◽

Slip Systems

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Deformation behaviour of cracked Strain-Hardening Cement-based Composites (SHCC) under sustained and repeated tensile loading

Creep, Shrinkage and Durability Mechanics of Concrete and Concrete Structures ◽

10.1201/9780203882955.ch64 ◽

2008 ◽

pp. 487-493 ◽

Cited By ~ 1

Author(s):

V Mechtcherine ◽

P Jun

Keyword(s):

Strain Hardening ◽

Deformation Behaviour ◽

Tensile Loading

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Investigation of a partial, inductive short-time heat treatment of thin metal sheets integrated into the forming process

MATEC Web of Conferences ◽

10.1051/matecconf/201819012008 ◽

2018 ◽

Vol 190 ◽

pp. 12008

Author(s):

Benjamin Clausius ◽

Petra Maier

Keyword(s):

Heat Treatment ◽

Strain Hardening ◽

Sheet Thickness ◽

Local Strain ◽

Single Step ◽

Thin Metal ◽

Recrystallization Annealing ◽

Forming Process ◽

Metal Sheets ◽

Short Time

Flanging is a widespread method in the sheet metal working industry to connect same or different materials by forming. Especially the sealing technology makes high demands on the flanging process: a low sheet thickness of the inner eyelet is necessary for proper sealing. The outer edges of the neck rings are mostly manufactured by shear cutting. The quality of the cut surface and the level of the local strain hardening influence decisively the limit of the flanging process by possible cracking. This paper is focused on the dependencies of these factors regarding thin metal sheets of different materials with a thickness down to 100 μm. It could be shown that strain hardening has a stronger effect on the process limits compared to the notch effect of the sheet edges when using standard values for the clearance of the shear cutting tool. Furthermore, a process is investigated with a partial inductive short-time heat treatment of the most deformed edge area. Due to the low thickness of the material and low heat capacities related thereto, it is possible to integrate a recrystallization annealing as single step into the forming process. As a result, the strain hardening can be removed from the affected zone directly between two forming steps to increase the process limits.

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