Solidification microstructures near the limit of absolute stability

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Metallurgical Transactions, (Section) A: Physical Metallurgy and Materials Science; (USA)

DOI:https://doi.org/10.1007/BF02667594· OSTI ID:5217433

Trivedi, R ^[1]; Sekhar, J A ^[2]; Seetharaman, V ^[3]

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1. Ames Lab., IA (USA)
2. Cincinnati Univ., OH (USA). Dept. of Materials Science and Engineering
3. Universal Energy Systems, Inc., Dayton, OH (USA)

A theoretical model of microstructural transitions in a binary alloy is examined to establish the conditions under which dendritic to cellular to planar interface transitions occur at high imposed growth rates. Critical experimental studies then are carried out in a transparent carbon-tetrabromide system to study the changes in microstructures which occur in the velocity regime where the planar interface is unstable. Low velocity transitions from a planar to cellular to dendritic structure and the high velocity transition from dendritic to microcellular structure are observed in situ. It is shown that these microstructural transitions occur continuously as the growth rate is increased. A reverse transition, from microcellular to dendritic structure with an increase in composition at a given velocity, also is observed. These results then are compared with the theoretical model.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5217433
• Journal Information: Metallurgical Transactions, (Section) A: Physical Metallurgy and Materials Science; (USA), Journal Name: Metallurgical Transactions, (Section) A: Physical Metallurgy and Materials Science; (USA) Vol. 20A; ISSN MTTAB; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOY SYSTEMS
BINARY ALLOY SYSTEMS
BROMIDES
BROMINE COMPOUNDS
CARBON COMPOUNDS
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INTERFACES
MICROSTRUCTURE
NUMERICAL DATA
PHASE TRANSFORMATIONS
SOLIDIFICATION
THEORETICAL DATA