scholarly journals Improvement of strength and ductility synergy in a room-temperature stretch-formable Mg-Al-Mn alloy sheet by twin-roll casting and low-temperature annealing

2021 ◽  
Author(s):  
T. Nakata ◽  
C. Xu ◽  
K. Kaibe ◽  
Y. Yoshida ◽  
K. Yoshida ◽  
...  
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Alloy Sheet ◽  
Twin Roll Casting ◽  
Low Temperature Annealing ◽  
Roll Casting ◽  
Twin Roll ◽  
Strength And Ductility

Microstructures and Mechanical Properties of AZ31+Sr+Y Magnesium Alloy Sheets Produced by Twin-Roll Casting and Sequential Hot Rolling

2013 ◽  
Vol 765-767 ◽  
pp. 3176-3179 ◽  
Author(s):  
Yan Dong Yu ◽  
Qiong Hu ◽  
Peng Jiang
Keyword(s):  
Magnesium Alloy ◽  
Hot Rolling ◽  
Room Temperature ◽  
Dominant Role ◽  
Boundary Slip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Deformation Properties ◽  
Increasing Temperature ◽  
Twin Roll

In this paper, the deformation properties of AZ31+Sr+Y magnesium alloy sheets produced by twin-roll casting (TRC) and sequential hot rolling were studied by the tensile testing at a strain rate of 7×10-4s-1and various temperatures: room temperature (RT), 200°C, 300°C and 400°C, respectively. The result shows that the microstructure of AZ31+Sr+Y alloy was refined obviously by adding elements Sr and Y, the elongation of the alloy increased with increasing temperature, and the fracture behavior of the alloy changed from brittle fracture to ductile fracture with increasing temperature. During the process of plastic deformation of AZ31+Sr+Y alloy, the twin plays a leading role at room temperature; the dislocation movement is regarded as the main deformation mechanism at 200° C; at the higher temperature (above 300°C) the grain boundary slip (GBS) plays a dominant role .

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.

A Decoupling Control Model on Perturbation Method for Twin-Roll Casting Magnesium Alloy Sheet

2015 ◽  
Vol 31 (5) ◽  
pp. 517-522 ◽  
Author(s):  
Wenyu Zhang ◽  
Dongying Ju ◽  
Hongyang Zhao ◽  
Xiaodong Hu ◽  
Yao Yao ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Perturbation Method ◽  
Control Model ◽  
Alloy Sheet ◽  
Decoupling Control ◽  
Magnesium Alloy Sheet ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

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

scholarly journals Effect of Cooling Rate on Microstructure and Properties of Twin-Roll Casting 6061 Aluminum Alloy Sheet

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1168 ◽  
Author(s):  
Zhen Xu ◽  
Sixue Wang ◽  
Hongbin Wang ◽  
Hua Song ◽  
Shengli Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Aluminum Alloy ◽  
Cooling Rate ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
6061 Aluminum Alloy ◽  
Microstructure And Properties ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

In this study, a twin-roll casting sheet of 6061 aluminum alloy was cooled using furnace, asbestos, air, wind and water. The effect of cooling rate on the microstructure and properties of twin-roll casting 6061 aluminum alloy sheet were studied. Optical microscope, scanning electron microscope, X-ray diffraction, microhardness tester and universal tensile machine were used to observe the microstructure and properties of twin-roll casting sheet of 6061 aluminum alloy. The results show that the higher the cooling rate, the smaller the grain size of the alloy and the smaller the number of precipitated phases in the matrix. Uniform grain size of the alloy could be obtained at a stable cooling rate. The hardness, tensile strength and elongation of the twin-roll casting sheet increased with cooling rate. Under wind cooling condition, the twin-roll casting sheet demonstrated excellent comprehensive performance, i.e., 88 MPa of yield strength, 178 MPa of tensile strength and 15% of elongation, respectively. A quantitative Hall–Petch relation was established to predict the yield strength of 6061 twin-roll casting sheets with different grain sizes and cooling rate.

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.

Microstructure and Mechanical Properties of High Aluminum Content Magnesium Alloys Fabricated by Twin-Roll Casting Process

2010 ◽  
Vol 638-642 ◽  
pp. 1608-1613
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Ryoji Nakamura ◽  
Keith Davey ◽  
Nobuhio Koga
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Hot Rolling ◽  
Weight Ratio ◽  
Alloy Sheet ◽  
Roll Speed ◽  
Simple Method ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

This paper describes the twin roll casting technology of magnesium alloys that contains relatively high weight ratio of aluminum, such as AM60, AZ91 and AZ121. The cast magnesium alloy sheets were hot-rolled in an elevated temperature to investigate the appropriate hot-rolling conditions for producing high-quality strip using a purpose-built strip-casting mill. The influences of such process parameters as materials of roll, casting temperature, and roll speed are ascertained. A simple method of predicting the convection heat transfer coefficient between casting rolls and molten metal is introduced. The microstructure of the manufactured wrought alloy sheets was observed to investigate the effects of the hot-rolling and heat-treatment conditions on crystal growth in the cast products. It is found that manufacturing thin magnesium alloy sheet was possible at a roll speed of 110m/min by a vertical type roll caster. The grain size of the manufactured wrought magnesium alloys sheet was less than 30 micrometers due to rapid solidification in the proposed process.

The Development of Superplastic Magnesium Alloy Sheet

2010 ◽  
Vol 433 ◽  
pp. 273-279 ◽  
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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