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

2011 ◽  
Vol 690 ◽  
pp. 331-334 ◽  
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.

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.

scholarly journals Mechanical Properties and Formability of Ultrasonic Treated Twin Roll Casting Magnesium Alloy Sheet

2017 ◽  
Vol 46 (3) ◽  
pp. 622-626 ◽  
Author(s):  
Yu Kun ◽  
Xiong Hanqing ◽  
Dai Yilong ◽  
Teng Fei ◽  
Fan Sufeng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Alloy Sheet ◽  
Magnesium Alloy Sheet ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

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.

Twin-Roll Cast Al-Clad Magnesium Alloy

2009 ◽  
Vol 618-619 ◽  
pp. 467-470 ◽  
Author(s):  
A.K. Prasada Rao ◽  
K.H. Kim ◽  
J.H. Bae ◽  
Geun Tae Bae ◽  
Dong Hyuk Shin ◽  
...  
Keyword(s):  
Reaction Zone ◽  
Transverse Section ◽  
Intermetallic Phases ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Microstructural Investigation ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll Cast ◽  
Twin Roll

An attempt has been made to clad Mg alloy with Al by twin-roll casting. This was done by inserting an Al sheet between the roll and the Mg alloy melt during twin-roll casting. Microstructural investigation across the transverse section of the as-cast Al-clad Mg alloy sheet reveals a very good interfacial bonding between Al and the base Mg alloy. Annealing of the Al-clad Mg alloy sheet results in the formation of layers of various intermetallic phases along the Mg/Al interface. Subsequent rolling of the as-annealed sheet significantly improves the formability of the reaction zone, as evidenced by the cracking of the base Mg alloy before the cracking of the reaction zone.

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.

Research on the Rolling of AZ31 Strip Prepared by Twin Roll Casting

2009 ◽  
Vol 610-613 ◽  
pp. 844-847 ◽  
Author(s):  
Jian Wang ◽  
Bin Jiang ◽  
Pei Dao Ding ◽  
Guang Jie Huang ◽  
Fu Sheng Pan
Keyword(s):  
Thin Sheet ◽  
Rolling Process ◽  
Minimum Thickness ◽  
Small Thickness ◽  
Cast Strip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Az31 Sheet ◽  
Conventional Rolling ◽  
Twin Roll

The AZ31 thin sheet (minimum thickness less than 1mm) was obtained by rolling the cast strip which was prepared by vertical twin roll casting in this paper. Since the absolute deformation during rolling was smaller,due to the small thickness of the strip of 3mm, the rolling of cast strip was different from the conventional rolling process. It was found that homogenizing time at 400°C for the cast strip was 4h and reduction per pass should be 8-10% for producing thinner (1-1.5mm) rolled AZ31 sheet at 350°C. Mechanical properties of the sheet were equivalent to conventional rolling sheet’s.

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