Deterioration of mechanical properties for pre-corroded AZ31 sheet in simulated physiological environment

In the present work, cross-wavy bending at room temperature was carried out to tailor the microstructure and stretch formability of rolled AZ31 sheets. Wavy bending processing generates profuse {10–12} twins and a tilt basal texture. Subsequent recrystallization annealing causes grain coarsening and enhances the intensity of twin-orientation. The combined use of wavy bending and annealing can maintain high tensile ductility and remarkably enhances the stretch formability of rolled AZ31 sheet. It can be mainly attributed to the non-basal texture in the wavy bent sheet which increases the thinning capability during in-plane tension.

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Solidification Microstructure and Mechanical Properties of Hot Rolled and Annealed Mg Sheet Produced through Twin Roll Casting Route

Materials Science Forum ◽

10.4028/www.scientific.net/msf.690.331 ◽

2011 ◽

Vol 690 ◽

pp. 331-334 ◽

Cited By ~ 17

Author(s):

M. Aljarrah ◽

Elhachmi Essadiqi ◽

D.H. Kang ◽

In Ho Jung

Keyword(s):

Mechanical Properties ◽

Fuel Efficiency ◽

Direct Chill ◽

Alloy Sheet ◽

Process Conditions ◽

Twin Roll Casting ◽

Roll Casting ◽

Average Grain Size ◽

Az31 Sheet ◽

Twin Roll

The use of wrought magnesium for automobile structural components is an important component of the mass reduction strategy for automobiles to improve their fuel efficiency. Compared to Direct chill casting, Twin Roll Casting (TRC) allows major reduction of hot rolling steps in the production of Mg sheet due to the thin thickness of the as-cast strip. This TRC route can substantially reduce the time and cost to produce Mg alloy sheet product. In this work, AZ31 magnesium alloy was casted to 5 and 6 mm thick strips under different process conditions. Microstructure of these strips was analyzed using optical microscopy, SEM and EPMA. TRC strip was annealed under two different conditions: 2 hours at 330 and 1 hour at 400°C. It has been found that heat treatment at 400°C for 1 hour reduces centerline segregation significantly. TRC strips were rolled down to 2 mm and annealed at 450°C for 2 minutes. The average grain size was 4-6 µm and mechanical properties were comparable with commercial AZ31 sheet.

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Numerical/experimental investigation of bulge tests on a localized laser heat-treated magnesium alloy AZ31 sheet

10.25518/esaform21.1555 ◽

2021 ◽

Author(s):

Pasquale Guglielmi ◽

Donato Sorgente ◽

Gianfranco Palumbo

Keyword(s):

Mechanical Properties ◽

Thickness Distribution ◽

Experimental Tests ◽

Local Variation ◽

Alloy Sheet ◽

Laser Source ◽

Laser Heat ◽

Heat Treated ◽

Az31 Sheet ◽

Square Spot

Lightweight alloys can be considered among the most promising materials thanks to their capability to reduce the environmental impact, without affecting mechanical properties. In addition, when very complex shapes are required, a viable strategy could be represented by the adoption of non-conventional forming processes applied to tailored blanks that allow to obtain local variation of the material properties. In fact, referred to the Mg alloys, both grain size and temperature strongly influence the deformation behavior, as well as the mechanical properties. In this work, the effects of a selective Laser Heat Treatment (LHT) on a Mg AZ31B-H24 alloy sheet were investigated both numerically and experimentally. Experimental tests were performed, using a Diode laser source and keeping a square spot stationary in the center of the sample. The microstructure evolution was evaluated by means of light microscopy. Subsequently, the heat-treated samples were subjected to bulge tests under superplastic conditions (450°C) and using pressurized argon gas. The experimental microstructure distributions obtained were used for the numerical bulge tests analyses performed in the same conditions of the experimental trials. Experimental LHT results showed the capability to locally modify the microstructure when suitable temperatures and interaction times are selected. Regarding the bulge tests, the obtained results showed the possibility to effectively affect the thickness distribution of the final shapes.

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The influence of the as-hot rolled microstructure on the elevated temperature mechanical properties of magnesium AZ31 sheet

Materials Science and Engineering A ◽

10.1016/j.msea.2007.10.064 ◽

2008 ◽

Vol 487 (1-2) ◽

pp. 243-250 ◽

Cited By ~ 40

Author(s):

G. Vespa ◽

L.W.F. Mackenzie ◽

R. Verma ◽

F. Zarandi ◽

E. Essadiqi ◽

...

Keyword(s):

Mechanical Properties ◽

Elevated Temperature ◽

Az31 Sheet ◽

Magnesium Az31 ◽

Hot Rolled

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Effect of Rolling and Annealing on the Mechanical Properties and Microstructure of AZ31 Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.379 ◽

2007 ◽

Vol 546-549 ◽

pp. 379-382

Author(s):

Guang Jie Huang ◽

Ling Yun Wang ◽

Guang Sheng Huang ◽

Fu Sheng Pan ◽

Qing Liu

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Hot Rolling ◽

Az31 Magnesium Alloy ◽

Final Thickness ◽

Microstructural Investigation ◽

Az31 Sheet ◽

Cold Rolling And Annealing ◽

Cold Rolled ◽

Hot Rolled

Microstructural evolution and mechanical properties of the AZ31 magnesium alloy during rolling and annealing process were investigated. The sheet samples were prepared after different stages of the hot rolling, cold rolling and annealing processes. The hot rolling temperature was between 300-450C and the final thickness of the cold rolled sheets was 1.5mm. The cold rolled sheets were annealed at different annealing temperature (260-350C) for different time (10~120min). Tensile test was performed to investigate the mechanical properties of the samples obtained from different stages. With aid of the optical microscopy, scanning electron microscopy (SEM) techniques, the microstructure of the samples were characterized and the results were related to the mechanical properties. It was found the hot-rolled sheets exhibit higher ductility comparing with the cold-rolled sheets. The microstructural investigation showed that the microstructure of the hot-rolled samples was dominated by recrystallized equiaxed grains while the microstructure of the cold-rolled samples dominated by deformation twining. By applying annealing on the cold-rolled sheets, fine recrystallization grains were obtained and ductility of the samples was improved. The effects of the grain size and twining on mechanical properties of the AZ31 sheet were further discussed based on the experimental results.

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The Effect of Differential Speed Rolling on Microstructure and Mechanical Properties of an AZ31 Alloy Sheet

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.235 ◽

2006 ◽

Vol 116-117 ◽

pp. 235-238 ◽

Cited By ~ 2

Author(s):

Ha Guk Jeong ◽

Y.G. Jeong ◽

Duk Jae Yoon ◽

Seo Gou Choi ◽

Woo Jin Kim

Keyword(s):

Mechanical Properties ◽

Az31 Alloy ◽

Rolling Process ◽

Alloy Sheet ◽

Microstructure And Mechanical Properties ◽

High Anisotropy ◽

Az31 Sheet ◽

Differential Speed Rolling ◽

Conventional Rolling ◽

Differential Speed

Magnesium alloy AZ31, which processed by conventional rolling or extrusion, has high anisotropy of mechanical properties in its strength and elongation at room temperature. We compared the influence of differential speed rolling with conventional rolling process on microstructure and mechanical properties of commercial AZ31 sheet. Commercial AZ31 alloy sheets were processed with conventional and differential speed rolled with thickness reduction ratio of 30% at a various temperature. The elongation of AZ31 alloy, warm-rolled by differential speed rolling is larger than rolled by conventional rolling. Besides, grain size and distribution on microstructure of the conventional rolling were coarsely(~30μm) and inhomogeneously but, that those of the differential speed rolling were fine(~13μm) and homogeneously.

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Effect of SiC Addition on the Mechanical Properties of Twin-Roll-Cast AZ31 Sheet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.622-623.575 ◽

2014 ◽

Vol 622-623 ◽

pp. 575-580 ◽

Cited By ~ 1

Author(s):

Kristina Neh ◽

Rudolf Kawalla

Keyword(s):

Mechanical Properties ◽

Grain Refinement ◽

Az31 Alloy ◽

Homogeneous Distribution ◽

Homogeneous Microstructure ◽

Twin Roll Casting ◽

Sic Particles ◽

Roll Casting ◽

Az31 Sheet ◽

Twin Roll

The effect of SiC addition on grain refinement of an AZ31 alloy was investigated. First preliminary casting tests were carried out. Different amounts between 0.25 wt% and 1,0 wt% of SiC-particles with a diameter of about 2 μm were added to an AZ31 melt and poured into a plate mould. The resulting microstructure was observed by optical microscopy. Best results were reached with the addition of about 0.25 wt% in terms of a homogeneous microstructure and a sufficient grain refinement. Higher amounts lead to coarsening and agglomeration of precipitations. Based on these results Twin-Roll-Casting (TRC) of an AZ31 alloy with the addition of SiC-particles was conducted. For the investigations a TRC-system in laboratory scale was used. This system is part of the Twin-Roll-Casting pilot plant at the Institute of Metal Forming, which is used in collaboration with the MgF Magnesium Flachprodukte GmbH. The produced TRC-strip was cut into plates, and samples for microstructure characterization and the determination of the mechanical properties were retrieved. Compared to TRC-strip without the addition of SiC-particles a microstructure with finer precipitations and a more homogeneous distribution can be observed. Furthermore, sheets with an addition of SiC offer improved mechanical properties in TRC-condition.

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