Mechanical Properties and Metallurgical Qualities of High Aluminum Content Magnesium Alloys Fabricated by Twin-Roll Casting

2010 ◽  
Vol 654-656 ◽  
pp. 1440-1443 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Mayumi Suzuki ◽  
Ryoji Nakamura ◽  
Nobuhio Koga ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Aluminum Content ◽  
Mg Alloys ◽  
Roll Speed ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
High Aluminum Content ◽  
Twin Roll ◽  
High Aluminum

This paper describes the twin-roll casting technology of magnesium alloys that contain relatively high weight ratios of aluminum, such as AZ91, AZ101 and AZ111. The magnesium alloy sheets were cast by a horizontal twin roll caster to manufacture relatively high-strength Mg alloys with high aluminum content. The influences of such process parameters as casting temperature and roll speed were ascertained. The microstructures of cast magnesium alloy sheets are observed to investigate the effects of roll-casting conditions on crystal growth in the cast products. It was found that Mg alloys with high aluminum content can be fabricated at a roll speed of 15 m/min with a horizontal-roll caster. The grain size of the manufactured wrought magnesium alloy sheet was about 10 micrometers due to rapid solidification in the proposed process.

Effects of Aluminum Content on Plastic Formability of Wrought Mg Alloy Sheet Produced by Twin-Roll Casting Process

2011 ◽  
Vol 675-677 ◽  
pp. 667-670 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Mayumi Suzuki ◽  
Toshio Haga ◽  
Keith Davey ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Aluminum Content ◽  
Alloy Sheet ◽  
Mg Alloys ◽  
Roll Speed ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
High Aluminum Content ◽  
Twin Roll ◽  
High Aluminum

A total weight reduction approach has been key issue for car manufacturers to cope with more and more stringent requirements for fuel economy. This paper describes the twin-roll casting technology of magnesium alloys that contain relatively high weight ratios of aluminum, such as AZ91,AZ101 and AZ111. The magnesium alloy sheets were cast by a horizontal twin roll caster to manufacture relatively high-strength Mg alloys with high aluminum content. The influences of such process parameters as casting temperature and roll speed were ascertained. The microstructures of cast magnesium alloy sheets were observed to investigate the effects of roll-casting conditions on crystal growth in the cast products. It was found that Mg alloys with high aluminum content can be fabricated at a roll speed of 15 m/min with a horizontal-roll caster. The grain size of the manufactured wrought magnesium alloy sheet was about 10 μm due to rapid solidification in the proposed process.

712 Twin roll casting of wrought high aluminum content Mg alloys

2012 ◽  
Vol 2012.20 (0) ◽  
pp. _712-1_-_712-5_
Author(s):  
Yuya YAMAMOTO ◽  
Hideto HARADA ◽  
Masaki ENDO ◽  
Shinichi NISHIDA ◽  
Mayumi SUZUKI ◽  
...  
Keyword(s):  
Aluminum Content ◽  
Mg Alloys ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
High Aluminum Content ◽  
Twin Roll ◽  
High Aluminum

Effect of Aluminum Content on Mechanical Properties of Cast Magnesium Alloy Sheets Fabricated by Twin-Roll Casting

2010 ◽  
Vol 97-101 ◽  
pp. 1077-1080 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Ryoji Nakamura ◽  
Keith Davey ◽  
Nobuhio Koga
Keyword(s):  
Magnesium Alloy ◽  
Aluminum Content ◽  
Roll Speed ◽  
Vertical Roll ◽  
Roll Casting ◽  
High Aluminum Content ◽  
Cast Magnesium Alloy ◽  
Cast Magnesium ◽  
Twin Roll ◽  
High Aluminum

This paper describes the twin-roll casting technology of magnesium alloys that contain relatively high weight ratios of aluminum, such as AM60, AZ91 and AZ121. The magnesium alloy sheets were cast by a vertical roll caster to manufacture relatively high-strength Mg alloys with high aluminum content. The influences of such process parameters as roll materials, casting temperature, and roll speed were ascertained. A simple method of predicting the convection heat transfer coefficient between casting rolls and molten metal is introduced. The microstructures of cast magnesium alloy sheets are microscopically observed to investigate the effects of roll-casting conditions on crystal growth in the cast products. It was found that Mg alloys with high aluminum content can be fabricated at a roll speed of 90m/min with a vertical-roll caster. The grain size of the manufactured wrought magnesium alloy sheet was about 30 micrometers due to rapid solidification in the proposed process.

Kiss-Point Position Control of Solidification Layer and Process Optimization for Twin-Roll Casting of Magnesium Alloys

2011 ◽  
Vol 189-193 ◽  
pp. 3844-3851
Author(s):  
Wen Ping Weng ◽  
Kang Deng ◽  
Zhong Ming Ren ◽  
Qi Chen ◽  
Zhi Dong Chi ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Process Optimization ◽  
Strip Thickness ◽  
Alloy Strip ◽  
Roll Speed ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

The solidification and process optimization for twin-roll casting of magnesium alloys have been studied. Effects of roll speed, roller diameter, setback length and strip thickness on the position of the solidification front and the surface quality of strip were analyzed through experiments. A kiss-point model which considers the strip thickness, set-back length and roll speed was established to optimize process and enhance the surface quality of magnesium alloy strip. Results showed that the twin-roll casting process could be effectively stabilized and optimized under the direction of the model, and the defectless magnesium alloy strip was obtained.

Hot Forging of Roll-Cast Magnesium Alloys with High Aluminum Content

2018 ◽  
Vol 789 ◽  
pp. 187-194
Author(s):  
Sueji Hirawatari ◽  
Hisaki Watari ◽  
Shinichi Nishida ◽  
Mayumi Suzuki ◽  
Toshio Haga
Keyword(s):  
Grain Size ◽  
Magnesium Alloys ◽  
Aluminum Content ◽  
Hot Forging ◽  
Roll Casting ◽  
High Aluminum Content ◽  
Cast Magnesium ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
High Aluminum

This paper deals with characteristics of hot forging of twin roll cast magnesium alloyswhich have relatively high aluminum content. High tensile strength magnesium alloys containing 9 to12% aluminum, such as Mg-9%Al-1%Zn, Mg-10%Al-1%Zn, Mg-11%Al-1%Zn, andMg-12%Al-1%Zn have been made by twin roll casting. A new experiment was performed for hotforging of high strength magnesium alloys with high aluminum content was performed. From theresults, using magnesium alloys with high aluminum content yielded less compressive deformationresistance than AXM403. It was also demonstrated that hot forging of magnesium alloys with highaluminum content produces small magnesium crystals (about six micro meters) and crystallizedsubstances. The mean grain size of the microstructure of Mg-12%Al-1%Zn forged at 623K was lessten micrometers although that of the Mg-9%Al-1%Zn was about thirty micrometers. The small betaphase which precipitates in the twin roll cast Mg-12%Al-1%Zn was distributed uniformly comparingto Mg-9%Al-1%Zn. From the result of microscopic observation of the forged products, it has beenrecognised that the Hall-petch rule between mean grain size of forged materials and Vickers hardnesshas been proved. The effects of the dynamic recrystallization on the microstructures of the twin-rollcast products seem to be different in terms of aluminum content. Due to rapid cooling of twin-rollcasting process process, the fabricated magnesium material could be used for hot forging. By applyinga servo press machine, a hot-forging experiment was performed with development of high strengthmagnesium alloys. A novel material that show higher hardness have been fabricated by usingtwin-roll casting process. It has also been clarified that the aluminum content affect precipitation ofbeta phase as well as grain size.

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.

Casting of High Aluminum Content AM Series Magnesium Alloys by Using a Horizontal Twin Roll Caster

2020 ◽  
Vol 841 ◽  
pp. 340-345
Author(s):  
Hotaka Tozuka ◽  
Kanae Seki ◽  
Hisaki Watari ◽  
Toshio Haga
Keyword(s):  
Magnesium Alloys ◽  
Aluminum Content ◽  
Hot Forging ◽  
Original Material ◽  
Roll Casting ◽  
Average Grain Size ◽  
High Aluminum Content ◽  
Twin Roll Caster ◽  
Twin Roll ◽  
High Aluminum

In this paper, twin roll casting of magnesium alloys with high aluminum content such as, Mg-11 mass%Al-0.2 mass%Mn, Mg-12 mass%Al-0.2 mass%Mn, Mg-13 mass%Al-0.2 mass% have been performed for the purpose of use as an original material for hot forging. Also the mechanical properties of the cast materials were examined. A 10 miri-meters thick strip was cast by the use of a horizontal twin roll caster. The microscopic observation was conducted to investigate into the precipitation of the metal compounds such as Mg17Al12, and the Vickers hardness of the cast strips test were performed. From the result of the roll casting experiments, a 10 mm thick strip was continuously cast at a roll speed of 3.1 m/min. The average grain size of the casting strips was about 46 micron meters. When the aluminum content was 13%, the hardness of the twin roll cast (TRC) strips became 1.7 times higher than that of extruded AZ 31. Also, a uniaxial compression test at elevated temperature was conducted to obtain a true strain-true stress curve for examining possibility of direct hot forging (DHF) of TRC magnesium alloys with high aluminum content.

SUPERPLASTIC FORMABILITY OF AZ31 MAGNESIUM ALLOY SHEETS PRODUCED BY TWIN ROLL CASTING AND SEQUENTIAL HOT ROLLING

2013 ◽  
Vol 27 (19) ◽  
pp. 1341020
Author(s):  
YANDONG YU ◽  
KAI LIN ◽  
PENG JIANG
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Hot Rolling ◽  
Tensile Testing ◽  
Az31 Magnesium Alloy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Three Stages ◽  
The Common ◽  
Twin Roll

In this paper, superplastic tensile testing and gas bulging forming of AZ31 and AZ31 + Y + Sr magnesium alloys produced by twin roll casting (TRC) and sequential hot rolling were carried out. At 673 K, the superplastic formability of the TRC AZ31 magnesium alloy sheets added Y and Sr elements has improved significantly compared to the common TRC AZ31 sheets. Formations of cavities on the bulging part go through three stages of the nucleation, growth and aggregation, finally cavities merging lead to rupture at the top of the bulging part.

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.

Sign in / Sign up

Export Citation Format

Share Document