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

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.

2015 ◽  
Vol 620 ◽  
pp. 223-232 ◽  
Author(s):  
Sanjeev Das ◽  
N.S. Barekar ◽  
Omer El Fakir ◽  
Liliang Wang ◽  
A.K. Prasada Rao ◽  
...  

2011 ◽  
Vol 690 ◽  
pp. 331-334 ◽  
Author(s):  
M. Aljarrah ◽  
Elhachmi Essadiqi ◽  
D.H. Kang ◽  
In Ho Jung

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.


2019 ◽  
Vol 804 ◽  
pp. 53-57
Author(s):  
Hai Jian Wang ◽  
Zhi Pu Pei ◽  
Dong Ying Ju

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.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1713 ◽  
Author(s):  
Yong Li ◽  
Chen He ◽  
Jiadong Li ◽  
Zhaodong Wang ◽  
Di Wu ◽  
...  

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.


2020 ◽  
Vol 12 (5) ◽  
pp. 685-692 ◽  
Author(s):  
Jia Yao ◽  
Min Zha ◽  
Huiyuan Wang ◽  
Wei Lu

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.


2018 ◽  
Vol 918 ◽  
pp. 48-53 ◽  
Author(s):  
Olexandr Grydin ◽  
Mykhailo Stolbchenko ◽  
Maria Bauer ◽  
Mirko Schaper

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.


2009 ◽  
Vol 610-613 ◽  
pp. 844-847 ◽  
Author(s):  
Jian Wang ◽  
Bin Jiang ◽  
Pei Dao Ding ◽  
Guang Jie Huang ◽  
Fu Sheng Pan

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.


2011 ◽  
Vol 299-300 ◽  
pp. 368-371 ◽  
Author(s):  
Yan Dong Yu ◽  
Peng Jiang ◽  
Chao Li ◽  
Kai Lin

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.


2017 ◽  
Vol 46 (3) ◽  
pp. 622-626 ◽  
Author(s):  
Yu Kun ◽  
Xiong Hanqing ◽  
Dai Yilong ◽  
Teng Fei ◽  
Fan Sufeng ◽  
...  

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