1993 Fiscal Year Final Research Report Summary
A fundamental studies on wetting between molten metal and a chill block and crystal growth from the chill block
| Project/Area Number |
03650547
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属加工(含鋳造)
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| Research Institution | Hokkaido University |
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Principal Investigator |
KUDOH Masayuki Hokkaido University, Faculty of Engineering, Department of Metallurgical Engineering, Associate Professor, 工学部, 助教授 (00001248)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Solidification / Dip / Carbon steel / Non-ferrous alloy / Ripple mark / Shell / Uneven growth / Heat transfer simulation |
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| Research Abstract |
Using carbon steels, Al-Cu binary alloys, an Al-Si eutectic alloy, and a Sn-Sb binary alloy, a thin shell was formed by a dipping technique. The shape of the shell and the surface in the chill side of the shell were investigated.
Following results were obtained from experimental results.
(1) The pattern like a tortoise shell was formed in the surface of the chill side of the shell and corresponds to the concave region of the shell, in which solidification retarded. (2) An uneven shell was formed in a hypoperitectic carbon steel. (3) A chill zone was formed in the steel containing low carbon content and fine dendrites were formed in the steel containing high carbon content. Extended dendrites grew from the chill crystals and the fine dendrites. In a hypoperitectic carbon steel, the extended dendrites grew randomly based on the mixing of the chill crystals and the fine dendrites, so that solidification proceeded unevenly. (4) Ripple marks was formed in the surface of the chill side of the shell in Al-Cu binary alloys and an Al-Si alloy, but it weren't depend on the uneven growth of the shell. (5) Button marks were observed in the surface of the chill side of the shell in a Sn-Sb binary alloy and it corresponded to the convex region of the Sn-Sb shell. (6) An uneven growth occurred periodically in vertical and horizontal directions of the Al-Cu shell, but it was occurred only a horizontal direction of the Al-Si shell. (7) Heat resistance should be introduced to computer simulation in order to cause the uneven growth of the solidifying shell.
Considering from above results, there are two types of the shell fromation. One is that it depends directly on nucleation such as a Sn-Sb alloy. The other is that it depends on the correlation among nucleation, latent heat and solid deformation due to thermal stress.
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