2005 Fiscal Year Final Research Report Summary
High Speed Production Process of Magnesium Alloy Sheets using electric vibration and different speed rolling
| Project/Area Number |
15360076
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Production engineering/Processing studies
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| Research Institution | Oyama National College of Technology |
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Principal Investigator |
WATARI Hisaki Oyama National College of Technology, Department of Mechanical Engineering, Associate Professor, 機械工学科, 助教授 (90210971)
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| Co-Investigator(Kenkyū-buntansha) |
HAGA Toshio Osaka Institute of Technology, Department of Mechanical Engineering, Professor, 機械工学科, 教授 (00212134)
OHASHI Takahiro National Institute of Advanced Science and Technology, Research center, ものづくり先端技術研究センター, 統合技術研究チーム長 (80277821)
YAMAZAKI Takanori Oyama National College of Technology, Department of Mechanical Engineering, Research Associate, 機械工学科, 助手 (80342476)
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| Project Period (FY) |
2003 – 2005
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| Keywords | magnesium alloy / twin roll caster / strip casting / semi-solid / different speed rolling / electricvibration / solidification modeling / high aluminum contents |
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| Research Abstract |
The Magnesium alloys are expected to play an important role as next-generation materials, which have possibilities of contributing to lighten the total product weight when magnesium products can be used to replace aluminum and mild steel products. The specific density of magnesium alloy is about 2/3 that of aluminum and 1/4 of that of iron. When alloyed, magnesium has the highest strength-to-weight ratio of all the structural metals. Moreover, because of the ease of recycling of metallic materials, magnesium has received global attention from the standpoint of environmental preservation. Utilization of magnesium alloys has mainly depended on casting technology, for instance, thixso-forming because of its less workable characteristics due to the crystal structure of the hexagonal close-packed lattice. Recently, demands have been raised in automotive and electronics industries to reduce the total product weight. Unfortunately, the major barrier to greatly increased magnesium alloy use is still primarily high manufacturing cost. One of the keys to solving this problem is to develop semi-solid roll strip casting technology to manufacture. The following conclusions are obtained.
1)Sheet thicknesses of cast strips could be predicted by a simple 1-D solidification model. It is found that an appropriate roll gap should be decided by considering the predicted cast thicknesses and the mill stiffness of the twin roll caster.
2)A temperature of over 250℃ was necessary to keep a cast magnesium alloy sheet from cracking in the hot rolling process.
3)An appropriate annealing temperature is effective for homogenizing microstructure of rolled cast sheets after the strip casting process.
4)The grain size of the manufactured wrought magnesium alloys sheet was less than 10 micrometer. The obtained magnesium alloy sheet shows equivalent limiting drawing ratio in a warm drawing test.
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