Interface attachment kinetics in alloy solidification

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Metallurgical Transactions, A

DOI:https://doi.org/10.1007/BF02648954· OSTI ID:237776

Aziz, M J ^[1]

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1. Harvard Univ., Cambridge, MA (United States). Div. of Applied Sciences

The current status of the understanding of nonequilibrium interface kinetics during solidification is reviewed. Measurements of solute trapping and kinetic interfacial undercooling during rapid alloy solidification are accounted for by the continuous growth model (CGM) without solute drag. Disorder trapping has been predicted and observed in the rapid solidification of ordered intermetallic compounds. In systems that undergo either solute or disorder trapping, a transition from short-range diffusion-limited to collision-limited growth occurs, which originates in the reduced driving free energy for the formation of such metastable materials, resulting in three orders of magnitude change in the interface mobility. Applications to cellular and dendritic growth are discussed. A correlation is presented for estimating the diffusive speed--the growth rate necessary for substantial solute trapping--for alloy systems in which it has not, or cannot, be measured. The raw data for Si(Bi) solute trapping measurements to which many models have been compared are presented in the Appendix.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-89ER45401
• OSTI ID: 237776
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 3 Vol. 27; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
CHEMICAL COMPOSITION
CORRELATIONS
CRYSTAL STRUCTURE
DENDRITES
DIFFUSION
HEAT FLUX
INTERFACES
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
ORIENTATION
SOLIDIFICATION
SOLUTES
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
VELOCITY