Homogeneous nucleation ahead of the solid-liquid interface during rapid solidification of binary alloys

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(96)00035-3· OSTI ID:415413

Smith, P M; Elmer, J W ^[1]

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1. Lawrence Livermore National Lab., CA (United States)

In recent rapid solidification experiments on Al-5%Be alloys, a Liquid Phase Nucleation (LPN) model was developed to explain the formation of periodic arrays of randomly-oriented Be-rich particles in an Al-rich matrix. In the LPN model, Be droplets were assumed to nucleate in the liquid ahead of the solid-liquid interface, but no justification for this was given. Here the authors present a model which considers the geometric constraints (imposed by proximity to the interface) on the number of solute atoms available to form a nucleus. Calculations based on this model predict that nucleation of second-phase particles can be most likely a short distance ahead of the interface in immiscible binary systems such as Al-Be. As part of the nucleation calculations, a semi-empirical method of calculating solid-liquid surface tensions in binary systems was developed, and is presented in the Appendix.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 415413
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 10 Vol. 44; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
BERYLLIUM ALLOYS
DIFFUSION
DISTRIBUTION
LIQUID METALS
MATHEMATICAL MODELS
PARTICULATES
PRECIPITATION
SOLIDIFICATION
SOLUBILITY
SOLUTES
SUPERSATURATION
SURFACE TENSION