Numerical analysis of the rapid solidification of gas-atomized Al-8 wt pct Fe droplets

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02649231· OSTI ID:6612289

Kim, S G ^[1]; Shin, S H ^[2]; Suzuki, Toshio; Umeda, Takateru ^[3]

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1. Kunsan National Univ. (Korea, Republic of)
2. Sammi Steel Corp., Changwon (Korea, Republic of). Central Research Inst.
3. Univ. of Tokyo (Japan). Dept. of Metallurgy

A numerical analysis of the microstructural evolution of microcellular and cellular [alpha]-Al phase in gas-atomized Al-8 wt pct Fe droplets was represented. The two-dimensional (2-D) non-Newtonian heat transfer and the dendritic growth theory in the undercooled melt were combined, assuming a point nucleation on the droplet surface and the macroscopically smooth solid-liquid interface enveloping the cell tips. It reproduced the main characteristic features of the reported microstructures quite well and predicted a considerable volume fraction of thermal dendritic growth region in a droplet smaller than 10[mu]m if an initial undercooling was larger than 100 K. The volume fractions of the microcellular region, g[sub A], and the sum of the microcellular and cellular region, g[sub [alpha]], were predicted as functions of the heat-transfer coefficient, h, and the initial undercooling, [Delta]T. It was shown that g[sub A] and g[sub [alpha]], in the typical atomization processes with h = 0.1 to 1.0 W/cm[sup 2]K, are dominated by [Delta]T and h, respectively, but for h larger than 4.0 W/cm[sup 2] K, a fully microcellular structure can be obtained irrespective of the initial undercooling.

• OSTI ID: 6612289
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:12; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
DATA
INFORMATION
IRON ALLOYS
MICROSTRUCTURE
NUMERICAL DATA
PHASE TRANSFORMATIONS
SOLIDIFICATION
THEORETICAL DATA