Evaluation of dendrite morphology using fractal dimension

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420788
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Metal making/Resorce production engineering
• Research Institution: Akita University
• Principal Investigator: Ohsasa Kenichi 秋田大学, 工学(系)研究科(研究院), 教授 (90111153)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: Al基合金 / デンドライト組織 / フラクタル次元 / 無次元周囲長 / 部分凝固時間 / 透過率

Outline of Final Research Achievements

Fractal dimensions of dendrites were measured at the transverse, longitudinal and oblique cross sections in unidirectionally solidified Al base alloys. Fractal dimension of dendrites at each section with same local solidification time showed same values. This result enables to estimate the cooling rate easily from the observed dendrite structures. Furthermore, a dimensionless perimeter was also examined as another parameter for expressing the complexity of dendrites.Tension test was carried out for the specimens having the structures with different fractal dimension and dimensionless perimeter. Along with increase in fractal dimension and dimensionless perimeter, tensile strength increased. Permeability of solid-liquid coexisting zone with the fraction of solid at the start of eutectic reaction can be estimated.

Free Research Field

凝固工学