scholarly journals Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

2015 ◽  
Vol 620 ◽  
pp. 223-232 ◽  
Author(s):  
Sanjeev Das ◽  
N.S. Barekar ◽  
Omer El Fakir ◽  
Liliang Wang ◽  
A.K. Prasada Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Az31 Alloy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

scholarly journals Improving element uniformity and mechanical properties of Al-Mg-Si alloy fabricated by twin roll casting with superheat melt treatment

2022 ◽  
Author(s):  
Bowen Wei ◽  
Tao Jiang ◽  
Shiju Li ◽  
Youyun Zhang ◽  
Guangming Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Solute Concentration ◽  
Production Cycle ◽  
Second Phase ◽  
Twin Roll Casting ◽  
Melt Treatment ◽  
Roll Casting ◽  
Twin Roll

Abstract The effect of superheat melt treatment(SMT) on microstructure and properties of Al-Mg-Si alloy fabricated by twin roll casting(TRC) was analyzed using optical microscope, scanning electron microscopy, emission electron probe micro analyzer and transmission electron microscopy. SMT increased the subcooling degree of melt during TRC. The solidification microstructure with high dendrite density and small dendrite spacing was obtained. The second phase was evenly distributed between dendrites and the solute concentration gradient was decreased. Intergranular solute aggregation caused by Reynolds’ dilatancy in TRC slab was effectively suppressed. The homogeneous solute distribution of TRC slab with SMT can be realized by short-time homogenization heat treatment. The size of insoluble particles was greatly reduced. The complete decomposition of non-equilibrium eutectic phase increased the solute concentration in α-Al, which promoted the precipitation of precipitates during aging heat treatment. The tensile strength and yield strength of T6 slab were improved, while the uniform elongation are almost not decreased. The strength and uniform of slab in T4P state were both improved. The obtained results can help further shorten the production cycle of TRC slabs and improve mechanical properties.

scholarly journals Corrosion Behavior and Mechanical Properties of Mg-Based Alloys by Rapid Solidification Technology of Twin Roll Casting

2019 ◽  
Vol 804 ◽  
pp. 53-57
Author(s):  
Hai Jian Wang ◽  
Zhi Pu Pei ◽  
Dong Ying Ju
Keyword(s):  
Mechanical Properties ◽  
Rapid Solidification ◽  
Corrosion Behavior ◽  
Crystalline Phase ◽  
Az31 Alloy ◽  
Dual Phase ◽  
Alloy Strip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

Mg-based alloys were prepared by rapid solidification of twin roll casting (TRC) which shows that the Mg-RE alloy expressed the quasi-amorphous phased and fine crystalline phase dual-phase material. Corrosion behavior of Mg-Based alloy in 3.5% NaCl solution after 48h immersion and mechanical properties were investigated. The result show that The Mg-RE alloy strip exhibited good corrosion resistance and higher ultimate tensile strength and elongation comparing to the AZ31 alloy strips. The elongation of Mg-RE alloy strip is also high than the AZ91 and ZK61 under powder metallurgy processing. These indicate that Mg-RE alloy produced by our method has a better ductility. This may due to the special microstructure of the Mg-RE alloy forms, i.e., quasi-amorphous phase plus fine crystalline phase dual phase state.

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

2014 ◽  
Vol 622-623 ◽  
pp. 575-580 ◽  
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.

Improving Mechanical Properties of Twin-Roll Cast AZ31 by Wire Rolling

2021 ◽  
Vol 1016 ◽  
pp. 957-963
Author(s):  
Marie Moses ◽  
Madlen Ullmann ◽  
Rudolf Kawalla ◽  
Ulrich Prahl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Rolling Texture ◽  
Total Elongation ◽  
Roll Casting ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Set Up ◽  
Twin Roll Cast ◽  
Twin Roll

Since 2018, the institute of metal forming has been studying the novel twin-roll casting (TRC) of magnesium wire at the pilot research plant set up specifically for this purpose. Light microscopic and scanning electronic investigations were carried out within this work and show the unique microstructure of twin-roll cast AZ31 magnesium alloy with grain sizes of about 10 μm ± 4 μm in centre and 39 μm ± 26 μm near the surface of the sample. By means of a short heat treatment (460 °C/15 min), segregations can be dissolved and grain size changes in centre to 19 μm ± 12 μm (increase) and near the surface to 12 μm ± 7 μm (decrease). Further, the mechanical properties of the twin-roll cast and heat-treated wire were analysed by tensile testing at room temperature. By heat treatment, the total elongation could be increased by a third whereas the strength decreases slightly. In heat-treated state, no preferred orientation is evident. In addition to the twin-roll cast and the heat-treated condition, the rolled state was analysed. For this purpose, the twin-roll cast wire was hot rolled using an oval-square calibration. After hot rolling, a dynamic recrystallization and grain refinement of the twin-roll cast wire could be achieved. It can be seen, that an increase in strength as well as in total elongation occur after wire rolling. Beside this, a rolling texture is evident.

scholarly journals A Novel Approach to Improve the Microstructure and Mechanical Properties of Al–Mg–Si Aluminum Alloys during Twin-Roll Casting

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1713 ◽  
Author(s):  
Yong Li ◽  
Chen He ◽  
Jiadong Li ◽  
Zhaodong Wang ◽  
Di Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Crystallization Front ◽  
Alloying Elements ◽  
Cast Slab ◽  
Energy Dispersion Spectroscopy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll Cast ◽  
Twin Roll

The main purpose of this present study was to investigate the different processing conditions on the microstructure, segregation behavior of alloying elements, and mechanical properties of Al−Mg−Si alloy twin-roll cast slab prepared using a novel twin-roll casting technology. The simulation of temperature field, distribution of alloying elements, tensile properties, hardness, and conductivity were examined by a Leica optical microscope, scanning electron microscopy, energy dispersion spectroscopy, electron probe microanalysis, and tensile tests. The results indicated that when the traditional twin-roll casting method was used to produce aluminum alloy strip, there are obvious centerline segregation defects due to the deep crystallization front depth and symmetrical solidification characteristics. When the forced-cooling technology was applied in the twin-roll casting process, by virtue of the changing of crystallization front depth and crystallization front shape, the segregation defects are obviously suppressed. Suggesting that this method can significantly improve the uniformity of alloying elements in the thickness direction of the twin-roll cast slab, ultimately improve the mechanical properties of AA6022 aluminum alloy.

Influence Research of Al and Zn Addition for Twin Roll Casting Magnesium During Multi-Pass Hot Rolling

2020 ◽  
Vol 12 (5) ◽  
pp. 685-692 ◽  
Author(s):  
Jia Yao ◽  
Min Zha ◽  
Huiyuan Wang ◽  
Wei Lu
Keyword(s):  
Hot Rolling ◽  
Texture Evolution ◽  
Az31 Alloy ◽  
Thickness Reduction ◽  
Twin Roll Casting ◽  
Texture Intensity ◽  
Pinning Effect ◽  
Roll Casting ◽  
Zn Addition ◽  
Twin Roll

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.

scholarly journals Asymmetric Twin-Roll Casting of an Al-Mg-Si-Alloy

2018 ◽  
Vol 918 ◽  
pp. 48-53 ◽  
Author(s):  
Olexandr Grydin ◽  
Mykhailo Stolbchenko ◽  
Maria Bauer ◽  
Mirko Schaper
Keyword(s):  
Mechanical Properties ◽  
Casting Process ◽  
Rolling Process ◽  
Age Hardening ◽  
Process Conditions ◽  
Shear Stresses ◽  
Asymmetric Rolling ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

The industrial application of high-alloyed Al-Mg-Si alloys for the production of thin strips by means of twin-roll casting is limited due to the structural inhomogeneity and segregation formation. To reach the highest mechanical properties of the finished product, a direct influence on the strip formation conditions during the twin-roll casting can be applied. Analogous to the asymmetric rolling process, additional shear stresses were created in the strip forming zone by using different circumferential velocities and torques of the caster rolls. To provide the asymmetric process conditions, only one caster roll was left driven and the second one was left idling during the casting process. The microstructure and the mechanical properties of the strips in the as-cast state as well as after the homogenization and subsequent age-hardening were analyzed. A comparison of the test results showed a positive influence of the asymmetry conditions on the strips’ properties.

Deformation Behaviour of AZ31 Magnesium Alloy Sheets Produced by Twin-Roll Casting and Sequential Hot Rolling

2011 ◽  
Vol 299-300 ◽  
pp. 368-371 ◽  
Author(s):  
Yan Dong Yu ◽  
Peng Jiang ◽  
Chao Li ◽  
Kai Lin
Keyword(s):  
Strain Rate ◽  
Hot Rolling ◽  
Az31 Alloy ◽  
Grain Boundary Sliding ◽  
Uniaxial Tensile ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Deformation Properties ◽  
Increasing Temperature ◽  
Twin Roll

AZ31 alloy sheets were produced by twin-roll casting (TRC) and sequential hot rolling. Uniaxial tensile tests were used to evaluate the deformation properties of the AZ31 alloy at a strain rate of 7×10-4s-1 and a temperature range from room temperature to 400°C. The microstructure evolution and fracture behaviour were observed by optical microscopy and scanning electronic microscope. The results show that the elongation of the AZ31 alloy increases with increasing temperature at a strain rate of 7×10-4s-1. The AZ31 alloy begins to exhibit superplasticity at 300°C. The elongation of 497.8% is achieved at 400°C. The deformation of the AZ31 alloy at low temperature is controlled by dislocation motion, and with increasing temperature (above 300°C), grain boundary sliding (GBS) begins to play a dominant role during superplastic deformation.

Influence of Heat-Treatment and Rolling Conditions on the Mechanical Warm Forming Properties of Twin-Roll Cast AZ31

2017 ◽  
Vol 746 ◽  
pp. 184-191 ◽  
Author(s):  
Franz Berge ◽  
Marie Moses ◽  
Rudolf Kawalla ◽  
Madlen Ullmann
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Hot Rolling ◽  
Tensile Deformation ◽  
Warm Forming ◽  
Efficient Production ◽  
Research Strategies ◽  
Component Design ◽  
Roll Casting ◽  
Twin Roll

Magnesium sheets are used for wide-ranging applications in the automotive sector. In contrast to conventional magnesium processing routes for strips, twin-roll casting (TRC) and hot rolling is a cost-efficient production process for magnesium strips and sheets. As part of previous research strategies, the optimization of the thermomechanical treatment of magnesium alloys has resulted in excellent mechanical properties for the component design. However, the previously determined results at room temperature cannot be correlated with the warm forming behaviour during the component production. This is due to different deformation mechanisms, which are active at various temperatures. For TRC material, there is a lack of knowledge about the influence of heat-treatment and rolling on the final mechanical properties at hot working temperatures. This article depicts the investigations done on the influence of heat-treatment and hot rolling conditions on the mechanical properties of AZ31 strips at tensile deformation temperatures of 20 °C and 300 °C.

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