Stability of eutectic interface during directional solidification

Thesis/Dissertation · Tue Apr 23 04:00:00 EDT 1996

DOI:https://doi.org/10.2172/219521· OSTI ID:219521

Han, Seung Hoon ^[1]

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1. Iowa State Univ., Ames, IA (United States)

Directional solidification of eutectic alloys shows different types of eutectic morphologies. These include lamellar, rod, oscillating and tilting modes. The growth of these morphologies occurs with a macroscopically planar interface. However, under certain conditions, the planar eutectic front becomes unstable and gives rise to a cellular or a dendritic structure. This instability leads to the cellular/dendritic structure of either a primary phase or a two-phase structure. The objective of this work is to develop a fundamental understanding of the instability of eutectic structure into cellular/dendritic structures of a single phase and of two-phases. Experimental studies have been carried out to examine the transition from a planar to two-phase cellular and dendritic structures in a ceramic system of Alumina-Zirconia (Al₂O₃-ZrO₂) and in a transparent organic system of carbon tetrabromide and hexachloroethane (CBr₄-C₂Cl₆). Several aspects of eutectic interface stability have been examined.

• Research Organization: Ames Lab., IA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 219521
• Report Number(s): IS-T--1764; ON: DE96009559
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
BROMIDES
CARBON COMPOUNDS
CHLORIDES
EUTECTICS
INSTABILITY
INTERFACES
MICROSTRUCTURE
SOLIDIFICATION
ZIRCONIUM OXIDES