Improvement of Magnesium Sheet Formability by Alloying Addition of Rare Earth Elements

The influences of rare earth elements addition on the crystallographic texture and microstructural evolutions are examined during rolling and annealing of Mg-sheets. In case of Nd or Y additions, dynamic recrystallisation is suppressed such that the deformed microstructure is observed after hot rolling with relatively large strain per pass. Cold rolled binary Mg-Nd alloy sheet shows strong texture with splitting of the basal poles in the rolling direction, however, the texture intensity decreases significantly during the recrystallisation annealing. From the comparison of deep drawing behaviours between commercial ZE10 and AZ31 sheets, it is observed that the addition of the rare earth elements and accompanying texture changes result in the improved formability.

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Influence of Rare Earth Addition on Texture Development during Static Recrystallization and Mechanical Behaviour of Magnesium Alloy Sheets

Materials Science Forum ◽

10.4028/www.scientific.net/msf.702-703.651 ◽

2011 ◽

Vol 702-703 ◽

pp. 651-654

Author(s):

Sang Bong Yi ◽

Lilian Rayas ◽

Stefanie Sandlöbes ◽

Stefan Zaefferer ◽

Dietmar Letzig ◽

...

Keyword(s):

Rare Earth ◽

Grain Growth ◽

Static Recrystallization ◽

Shear Bands ◽

Rare Earth Addition ◽

Axial Tensile ◽

Sheet Formability ◽

Cold Rolled ◽

Basal Type

The role of rare earth addition on the microstructure and texture during recrystallization of cold rolled sheets is investigated by a comparative study of pure Mg, Mg-3Y and Mg1.5Nd sheets. In pure Mg, nucleation occurs mainly at shear bands which results in a texture weakening. The basal-type texture re-strengthens rapidly during grain growth of the pure Mg sheet. In contrast, in the Mg-RE alloys the weaker texture formed during early recrystallization strage is retained during further annealing due to retarded grain growth. Uni-axial tensile and Erichsen tests show that ductility and sheet formability are significantly improved by addition of rare earth elements.

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Critical Rolling Process Parameters for Dynamic Recrystallization Behavior of AZ31 Magnesium Alloy Sheets

Materials ◽

10.3390/ma11102019 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2019

Author(s):

Wenke Wang ◽

Qing Miao ◽

Xuemin Chen ◽

Yang Yu ◽

Wencong Zhang ◽

...

Keyword(s):

Magnesium Alloy ◽

Dynamic Recrystallization ◽

Process Parameters ◽

Rolling Direction ◽

Rolling Process ◽

Alloy Sheet ◽

Rolling Temperature ◽

Az31 Magnesium Alloy ◽

Texture Intensity ◽

C 30

In this work, the influence of various rolling temperatures and thickness reductions on the dynamic recrystallization (DRX) behavior of AZ31 magnesium alloy sheets was investigated. Meanwhile, the texture variation controlled by DRX behavior was analyzed. Results suggested that, with the help of DRX behavior, reasonable matching of rolling temperature and thickness reduction could effectively refine the grain size and improve the microstructure homogeneity. Using the grain refinement and microstructure homogeneity as the reference, the critical rolling process parameters were 400 °C—30%, 300 °C—30%, and 250 °C—40% in the present work. In terms of basal texture variation, the occurrence of twins produced the largest maximum texture intensity. However, for the sheets with DRX behavior, the maximum texture intensity decreased sharply, but would steadily increase with the growth of DRXed grain. Additionally, for DRXed grains, the <11-20>//RD (RD: rolling direction) grains would gradually annex the <10-10>//RD grains with the growth of DRXed grains, which finally made their texture component become the dominant texture state. However, when the deformation continued, the <10-10> in DRXed grains would rotate toward the RD again. Weighted by the fracture elongation of AZ31 magnesium alloy sheet, the critical thickness reductions were 30–40% under the rolling temperature of 400 °C.

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Dynamic Tension Deformation of Rare-Earth Containing Mg-1.9Mn-0.3Ce Alloy Sheet along the Rolling Direction at Various Temperatures

Metals ◽

10.3390/met10111473 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1473

Author(s):

Jin Wang ◽

Yang Wang ◽

Ziran Li

Keyword(s):

Rare Earth ◽

Strain Rate ◽

Rate Increase ◽

Rolling Direction ◽

Alloy Sheet ◽

Prismatic Slip ◽

Ductile Mode ◽

Temperature Ranges ◽

Strain Responses ◽

Strain Hardening Rate

The tensile properties of rare-earth containing Mg-1.9Mn-0.3Ce alloy sheet along the rolling direction were experimentally investigated within the strain rate and temperature ranges of 0.001–1300 s−1 and 213–488 K. The obtained stress-strain responses of the alloy sheet indicate that both yield strength and strain-hardening rate increase when the strain rate increases, whereas they decrease with increase of temperature. Microscopic examination results show that basal slip, prismatic slip, and {101¯2} tension twinning take place in the tensile plastic deformation, while the occurrence of twinning is not obviously affected by the rate and temperature. Tensile samples tend to fracture in a ductile mode with increasing strain rate and temperature.

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Influence of Uniaxial Deformation on Texture Evolution and Anisotropy of 3104 Al Sheet with Different Initial Microstructure

Metals ◽

10.3390/met11111729 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1729

Author(s):

Sofia Papadopoulou ◽

Vasilis Loukadakis ◽

Zisimos Zacharopoulos ◽

Spyros Papaefthymiou

Keyword(s):

Tensile Testing ◽

Thermomechanical Processing ◽

Electron Backscatter Diffraction ◽

Texture Evolution ◽

Rolling Direction ◽

Alloy Sheet ◽

Microstructural Parameters ◽

Cold Rolled ◽

Underlying Mechanisms ◽

Microstructural Anisotropy

Optimum mechanical behavior is achieved by means of controlling microstructural anisotropy. The latter is directly related to the crystallographic texture and is considerably affected by thermal and mechanical processes. Therefore, understanding the underlying mechanisms relating to its evolution during thermomechanical processing is of major importance. Towards that direction, an attempt to identify possible correlations among significant microstructural parameters relating to texture response during deformation was made. For this purpose, a 3104 aluminum alloy sheet sample (0.5 mm) was examined in the following states: (a) cold rolled (with 90% reduction), (b) recovered and (c) fully recrystallized. Texture, anisotropy as well as the mechanical properties of the samples from each condition were examined. Afterwards, samples were subjected to uniaxial loading (tensile testing) while the most deformed yet representative areas near the fractured surfaces were selected for further texture analysis. Electron backscatter diffraction (EBSD) scans and respective measurements were conducted in all three tensile test directions (0°, 45° and 90° towards rolling direction (RD)) by means of which the evolution of the texture components, their correlation with the three selected directions as well as the resulting anisotropy were highlighted. In the case of the cold-rolled and the recovered sample, the total count of S2 and S3 components did not change prior to and after tensile testing at 0° towards RD; however, the S2 and S3 sum mostly consisted of S3 components after tensile testing whereas it mostly consisted of S2 components prior to tensile testing. In addition, the aforementioned state was accompanied by a strong brass component. The preservation of an increased amount of S components, and the presence of strain-free elongated grains along with the coexistence of a complex and resistant-to-crack-propagation substructure consisting of both high-angle grain boundaries (HAGBs) and subgrain boundaries (SGBs) led into an optimal combination of Δr and rm parameters.

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Statistical Analysis on Static Recrystallization Texture Evolution in Cold-Rolled AZ31 Magnesium Alloy Sheet

Microscopy and Microanalysis ◽

10.1017/s1431927613012257 ◽

2013 ◽

Vol 19 (S5) ◽

pp. 21-24 ◽

Cited By ~ 3

Author(s):

Jun-Ho Park ◽

Tae-Hong Ahn ◽

Hyun-Sik Choi ◽

Jung-Man Chung ◽

Dong-Ik Kim ◽

...

Keyword(s):

Magnesium Alloy ◽

Thermomechanical Processing ◽

Texture Evolution ◽

Rolling Direction ◽

Alloy Sheet ◽

Basal Texture ◽

Rolled Sample ◽

Az31 Magnesium Alloy Sheet ◽

Cold Rolled ◽

Grain Orientation Spread

AbstractCast AZ31B-H24 magnesium alloy, comprising Mg with 3.27 wt% Al and 0.96 wt% Zn, was cold rolled and subsequently annealed. Global texture evolutions in the specimens were observed by X-ray diffractometry after the thermomechanical processing. Image-based microstructure and texture for the deformed, recrystallized, and grown grains were observed by electron backscattered diffractometry. Recrystallized grains could be distinguished from deformed ones by analyzing grain orientation spread. Split basal texture of ca. ±10–15° in the rolling direction was observed in the cold-rolled sample. Recrystallized grains had widely spread basal poles at nucleation stage; strong {0001} basal texture developed with grain growth during annealing.

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Strain-Hardening Behavior of Mg-Li-Zn Alloy Thin Sheets under Tension

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.1361 ◽

2010 ◽

Vol 146-147 ◽

pp. 1361-1364 ◽

Cited By ~ 3

Author(s):

Horng Yu Wu ◽

Pin Hou Sun ◽

Chui Hung Chiu ◽

Geng Zhong Zhou

Keyword(s):

Strain Hardening ◽

Room Temperature ◽

Rolling Direction ◽

Tensile Tests ◽

Alloy Sheet ◽

Stage Ii ◽

Cold Rolled ◽

Strain Hardening Behavior ◽

Zn Alloy ◽

Li Content

This work examined the effects of Li content on the strain-hardening behaviors of three varieties of Mg−Li−Zn alloys containing approximately 6 wt%, 9 wt%, and 10 wt% of Li. Tensile tests were carried out on specimens in the directions of 0, 45 and 90° to the rolling direction. Kocks–Mecking type plots were constructed to illustrate different stages of strain-hardening. The cold-rolled Mg−6Li−1Zn (designated as LZ61) alloy sheet showed stage II and stage III strain-hardening behaviors at room temperature. The specimens of Mg−9Li−1Zn (designated as LZ91) and Mg−10Li−1Zn (designated as LZ101) alloy sheets did not show stage II strain-hardening. Higher initial strain-hardening rates were observed in the 90° direction for these alloys as a result of the cold-rolled fibrous structure affording stronger barriers to dislocation movements in this direction.

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Research on Microstructure and Room Temperature Plasticity of Mg94.5Zn4Y1Er0.5 Alloy Sheet

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.3207 ◽

2011 ◽

Vol 239-242 ◽

pp. 3207-3210

Author(s):

Zhong Jun Wang ◽

Yang Xu ◽

Jia Cheng ◽

Zhao Jing Wang ◽

Bao Hua Kang ◽

...

Keyword(s):

Tensile Strength ◽

Rare Earth ◽

Magnesium Alloy ◽

Rare Earth Elements ◽

Tensile Properties ◽

Room Temperature ◽

Transverse Direction ◽

Hot Extrusion ◽

Alloy Sheet ◽

Basal Texture

The microstructure and tensile properties at room temperature of as-extruded Mg94.5Zn4Y1Er0.5 alloy sheet were studied. The results show that the alloy is mainly composed of equiaxial-liked α-(Mg) grains and W phase containing lots of rare earth elements (F.C.C. structure, a=0.707nm). The elongation and tensile strength of the alloy sheet in hot extruded and transverse direction are 25.5 %, 29.9 % and 247 MPa, 240 MPa, respectively. The above results manifest that the W phase stimulate the DRX during hot extrusion, reduce the preference of basal texture of magnesium alloy, markedly improve the plastically shaping capability at room temperature.

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Enhancement of Press Formability of Rolled Mg Alloy Sheet by Using Cross Rolling Processes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.1615 ◽

2007 ◽

Vol 539-543 ◽

pp. 1615-1619

Author(s):

Yasumasa Chino ◽

Kensuke Sassa ◽

Akira Kamiya ◽

Mamoru Mabuchi

Keyword(s):

Rolling Direction ◽

Az31 Alloy ◽

Rolling Process ◽

Rolling Plane ◽

Alloy Sheet ◽

Cross Rolling ◽

Plane Normal ◽

Texture Intensity ◽

Roll Axis ◽

Press Formability

In this study, two different cross rolling processes, which are effective rolling processes for a reduction of (0002) plane texture, are introduced. In the first cross rolling process, a sheet specimen is rotated around the rolling plane normal after each pass. In the second cross rolling process, the roll axis is tilted against the transverse direction (TD) in the rolling direction (RD) - TD plane. The two cross-rolling processed were carried out on a AZ31 alloy, and the press formability of cross-rolled sheets was compared with that of unidirectionally rolled sheets determined by Erichsen tests at 433 – 493 K. Both the cross-rolled specimens exhibited a high press formability, compared to an unidirectionally rolled alloy. The high press formability of the specimen by the first cross rolling was due to a reduction in (0002) texture intensity. The high press formability of the specimen by the second cross rolling was due to not only a reduction in (0002) texture intensity but also grain refinement.

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