Aging Effect on Texture Evolution during Warm Rolling of ZK60 Alloys Fabricated by Twin-Roll Casting

This study was aimed at revealing the influence of Al and Zn additions on microstructure, texture evolution and mechanical properties of twin roll casting Mg during multi-pass hot rolling. Firstly, both pure Mg and AZ31 sheets were rolled 9 passes with ∼80% thickness reduction. More effective grain refinement in AZ31 compared to pure Mg after hot rolling, which caused by the pinning effect from fine Mg17Al12 particles present in AZ31 alloy. Meanwhile a strong basal texture gradually formed with increasing thickness reduction in pure Mg. With Al and Zn adding, the texture intensity of AZ31 was much lower than pure Mg in each rolling-pass. The 5th AZ31 sample features a maximum intensity of ∼12.9, which is reduced by 50.6% as compared to the value of ∼26.1 for pure Mg. Compared to pure Mg, the Al and Zn solutes and weakened texture in AZ31 favor the strong work hardening, which promotes a simultaneous high ultimate tensile strength of ∼270 MPa and ductility of ∼22% in the 5th AZ31 sample. The results will be helpful for the TRCed Mg alloys with huge potential for industrial application.

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Texture Evolution in Non-Oriented Silicon Steel Processed by Twin-Roll Casting

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.452-453.7 ◽

2012 ◽

Vol 452-453 ◽

pp. 7-11 ◽

Cited By ~ 1

Author(s):

Wei Pei ◽

Yu Hui Sha ◽

Fang Zhang ◽

Liang Zuo

Keyword(s):

Cold Rolling ◽

Texture Evolution ◽

Casting Process ◽

Rolling Process ◽

Silicon Steel ◽

Recrystallization Annealing ◽

Twin Roll Casting ◽

Steel Sheets ◽

Roll Casting ◽

Twin Roll

In this paper, non-silicon steel sheets were produced by both twin-roll casting method and conventional process. Orientation characteristics and texture evolution of the sheets during casting, cold rolling and recrystallization annealing were investigated for comparison. It was found that the subsurface of twin-roll casting strips are characterized by weak {100} orientation while the central layer by random orientation. Twin-roll casting process can decrease α fiber (//RD) and increase γ fiber (//ND) during cold rolling process. Consequently, the η fiber (//RD) favorable for magnetic properties of non-silicon steels is enhanced and the detrimental {111} component is suppressed after annealing.

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Microstructure and Texture Evolution during Twin-Roll Casting and Annealing of a Mg–6.8Y2.5Zn–0.4Zr Alloy (WZ73)

Crystals ◽

10.3390/cryst10060513 ◽

2020 ◽

Vol 10 (6) ◽

pp. 513 ◽

Cited By ~ 1

Author(s):

Kristina Kittner ◽

Madlen Ullmann ◽

Falko Arndt ◽

Rudolf Kawalla ◽

Ulrich Prahl

Keyword(s):

Grain Boundaries ◽

High Temperatures ◽

Texture Evolution ◽

Cast State ◽

Twin Roll Casting ◽

Roll Casting ◽

Average Grain Size ◽

Different Temperatures ◽

Twin Roll Cast ◽

Twin Roll

In the present work, the microstructure and texture of a Mg–6.8Y–2.5Zn–0.4Zr sheet manufactured by twin-roll casting were investigated. The twin-roll cast state consisted of two apparent phases: the α-Mg matrix, which was made up of dobulites with an average grain size of approximately 50 µm and the LPSO (long-period stacking ordered) phase, which formed network-like precipitates along the grain boundaries. After twin-roll casting, annealing was carried out under conditions of different temperatures ranging from 450 °C to 525 °C and holding times between 2 h and 24 h. It was found that heat treatment led to the formation of a microstructure in which grains were apparent. Furthermore, it could be observed that high temperatures > 500 °C led to changes in the morphology of the LPSO structures. On one hand, the network-like structure dissolved while, on the other hand, both rodlike and blocky LPSO phases precipitated predominantly at the grain boundaries of the α-Mg matrix. This process was fostered by high temperatures and long holding times.

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Three-Ply Al/Mg/Al Clad Sheets Fabricated by Twin-Roll Casting and Post-treatments (Homogenization, Warm Rolling, and Annealing)

Metallurgical and Materials Transactions A ◽

10.1007/s11661-016-3842-7 ◽

2016 ◽

Vol 48 (1) ◽

pp. 57-62 ◽

Cited By ~ 5

Author(s):

Jaeyeong Park ◽

Hyejin Song ◽

Jung-Su Kim ◽

Seok Su Sohn ◽

Sunghak Lee

Keyword(s):

Warm Rolling ◽

Twin Roll Casting ◽

Roll Casting ◽

Twin Roll

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Comparison of Precipitates and Texture Evolution in Nb-Bearing Grain-Oriented Silicon Steel Produced by Conventional Processing and Novel Twin-Roll Casting

Metals ◽

10.3390/met10081085 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1085

Author(s):

Yang Wang ◽

Yuanxiang Zhang ◽

Feng Fang ◽

Xiang Lu ◽

Guo Yuan ◽

...

Keyword(s):

Texture Evolution ◽

Secondary Recrystallization ◽

Niobium Nitride ◽

Silicon Steel ◽

Electron Backscattered Diffraction ◽

Twin Roll Casting ◽

Roll Casting ◽

Transmission Electron ◽

New Type ◽

Twin Roll

The Nb-bearing grain-oriented silicon steel sheets were produced by conventional route and novel twin-roll casting route, respectively. The microstructure, texture and precipitate evolution were comparatively investigated by using electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The findings revealed that the precipitation behavior and the texture evolution were totally different between the two processing routes. In the conventional route, a great number of nanoscale niobium nitride particles (NbN), which acted as mainly grain growth inhibitors were precipitated during hot rolling, while in the twin-roll casting route, due to the rapid solidification, the precipitation of NbN were suppressed and a new type Nb-bearing precipitate enriched with sulfur element was observed in the as-cast strip. Besides, the primary recrystallized texture of conventional specimens was characterized by strong γ-fiber with a peak at {111} <110>, together with very few Goss components. While in the case of twin-roll casting specimens, the strongest primary recrystallized texture was {111} <112> texture and the area fraction of Goss component was much higher than that of conventional specimens. After final high temperature annealing, complete secondary recrystallization was obtained in twin-roll casting specimens and the magnetic induction of B8 was 0.1 T higher than that of conventional specimens.

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Effect of Thermomechanical Processes on Twin Roll Casted Magnesium Alloy Sheets

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.369 ◽

2014 ◽

Vol 783-786 ◽

pp. 369-374

Author(s):

Ozgur Duygulu ◽

Selda Ucuncuoglu ◽

Gizem Oktay Secgin

Keyword(s):

Electron Microscopy ◽

Magnesium Alloy ◽

Tensile Tests ◽

Warm Rolling ◽

Age Hardening ◽

Forming Limit ◽

Casting Technique ◽

Twin Roll Casting ◽

Roll Casting ◽

Twin Roll

6 mm thick and 1500 mm wide magnesium alloy AZ31, AZ61, AZ91, AM50 and AM60 sheets were produced by twin roll casting technique. Sheets were homogenized between 350-475oC for 1-24 h. AZ31 sheets were rolled down to 1 mm by symmetrical warm rolling and asymmetric warm rolling. Age hardening was also performed on magnesium alloy AZ91 sheets. Specimens were aged at 100-300oC for up to 100 h. Characterization was performed by light microscope, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), transmission electron microscopy (TEM) and x-ray diffraction (XRD) after twin roll casting and also after each thermomechanical process including aging. Tensile tests and micro hardness tests were performed for mechanical properties. In addition to the room temperature tests, elevated temperature tensile tests were also performed at 100, 150, 200, 250, and 300oC at various deformation speeds. Forming limit diagram of the material was determined under warm forming condition.

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The Development of Superplastic Magnesium Alloy Sheet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.433.273 ◽

2010 ◽

Vol 433 ◽

pp. 273-279 ◽

Cited By ~ 4

Author(s):

Richard J. Dashwood ◽

David Klaumunzer ◽

Martin Jackson ◽

Zhong Yun Fan ◽

Roger Grimes

Keyword(s):

Magnesium Alloy ◽

Magnesium Alloys ◽

Warm Rolling ◽

Alloy Sheet ◽

Magnesium Alloy Sheet ◽

Twin Roll Casting ◽

Roll Casting ◽

Strip Cast ◽

Twin Roll ◽

Cast Condition

While magnesium alloys are routinely used in engineering applications in the form of net shape castings, applications for sheet product have been limited due to the poor cold formability of magnesium combined with the perceived expense of sheet. The issues associated with poor cold formability could largely be overcome if magnesium alloys were to be superplastically formed. Superplasticity in magnesium is well established with research papers on the subject dating back to the late 1960s. In recent years, interest in this area has grown to the point where a number of companies have successfully superplastically formed prototype automotive panels from magnesium alloy sheet. Concurrent to this the scientific community have demonstrated superplasticity in a wide range of magnesium alloys using processing techniques ranging from the exotic (severe plastic deformation) to the mundane (traditional warm rolling). Work by the current authors has shown, rather surprisingly, that superplasticity can be achieved in magnesium alloys in the as-cast condition. This has led to some initial exploratory work involving twin roll casting. The concept being that affordable superplastic magnesium sheet could be produced via twin roll casting with only limited rolling reduction to final gauge. This paper describes the superplastic behaviour (in uniaxial tension) and microstructure of sheet processed from strip cast AZ31 and AZ91. The experimental material has included strip cast AZ91 subjected to large shear strains immediately prior to casting. The material was tested in the as-cast condition and after warm rolling to a number of gauges. Industrially useful superplastic capability was demonstrated in the strip cast alloys. Furthermore, good superplastic capability was also demonstrated in sheet subsequently rolled from the cast metal and rolling strain did not significantly influence the ductilities obtained. The mechanism for achieving superplasticity in as-cast magnesium alloys will be considered and the contrasting deformation characteristics of AZ31 and AZ91 will be discussed in terms of m value analysis and microstructural characterisation.

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