1995 Fiscal Year Final Research Report Summary
Analysis for uniformity and spatial distribution structure of solidification structures using minimal spanning tree
Project/Area Number |
06650831
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Metal making engineering
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Research Institution | the University of Tokyo |
Principal Investigator |
SUZUKI Toshio School of Engineering, the University of Tokyo, professor, 大学院・工学系研究科, 教授 (70115111)
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Project Period (FY) |
1994 – 1995
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Keywords | minimal spanning tree / spatial distribution pattern / dendrite / nucleation / regularity |
Research Abstract |
Analysis for uniformity and spatial pattern distribution of solidification structures is investigated using minimal spanning tree (MST). The validity of MST analysis is at first clarified for the generated 2-dimensional point spatial patterns. The normalized mean values of edges and its standard variation of MST for the concerning pattern give the information for determining the pattern of the structure. The information on local node distribution is obtained from the histgrums of edge length and edge angle of MST.Fourie transform analysis also gives useful knowledge about the long range ordering of structures. The spatial pattern of primary dendrites in the unidirectionally solidified Ni-based superalloy. The spatial distribution of dendrites is dominated by an inihibitition rule when temperature gradient is small. When temperature gradient is large, dendrite pattern becomes regular and has the characteristics of a square lattice pattern. The nucleation point distribution of rapidly solidified alloys are also investigated. The regularity is found in the spatial pattern of nucleation points, though the pattern becomes random with increase of superheat of the melts.
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