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

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.

2018 ◽  
Vol 789 ◽  
pp. 187-194
Author(s):  
Sueji Hirawatari ◽  
Hisaki Watari ◽  
Shinichi Nishida ◽  
Mayumi Suzuki ◽  
Toshio Haga

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.


2010 ◽  
Vol 654-656 ◽  
pp. 1440-1443 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Mayumi Suzuki ◽  
Ryoji Nakamura ◽  
Nobuhio Koga ◽  
...  

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.


2012 ◽  
Vol 2012.20 (0) ◽  
pp. _712-1_-_712-5_
Author(s):  
Yuya YAMAMOTO ◽  
Hideto HARADA ◽  
Masaki ENDO ◽  
Shinichi NISHIDA ◽  
Mayumi SUZUKI ◽  
...  

2010 ◽  
Vol 97-101 ◽  
pp. 1077-1080 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Ryoji Nakamura ◽  
Keith Davey ◽  
Nobuhio Koga

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.


2013 ◽  
Vol 45 (2) ◽  
pp. 427-437 ◽  
Author(s):  
Hideto Harada ◽  
Shinichi Nishida ◽  
Endo Masaki ◽  
Hisaki Watari

2017 ◽  
Author(s):  
Tomohiro Kishi ◽  
Hisaki Watari ◽  
Mayumi Suzuki ◽  
Toshio Haga

2011 ◽  
Vol 675-677 ◽  
pp. 667-670 ◽  
Author(s):  
Hisaki Watari ◽  
Yoshimasa Nishio ◽  
Mayumi Suzuki ◽  
Toshio Haga ◽  
Keith Davey ◽  
...  

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.


2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari

An inline hot rolling was operated on 5182 aluminum alloy strip cast using a vertical type high speed caster (VHSTRC) at the speed of 60 m/min. A porosity existing at center line of the thickness and a ripple mark on the surface, these are typical defects of the strip cast by the VHSTRC, could be improved by the inline rolling. The rolling speed was as same as the roll-casting-speed of 60m/min. The temperature of the strip, when the inline rolling was operated, was 450oC. The reduction of the strip of the inline rolling was 35%.


Sign in / Sign up

Export Citation Format

Share Document