Morphological stability of a solid–liquid interface and cellular growth: Insights from thermoelectric measurements in microgravity experiments

• Published in: Journal of crystal growth Vol. 279; no. 1; pp. 195 - 205
• Main Authors: Garandet, J.P., Boutet, G., Lehmann, P., Drevet, B., Camel, D., Rouzaud, A., Favier, J.J., Faivre, G., Coriell, S., Alexander, J.I.D., Billia, B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2005; Elsevier
• Subjects: A1. Morphological stability; A2. Bridgman technique; A3. Microgravity conditions; B1. Metals; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth in microgravity environments; Materials science; Methods of crystal growth; physics of crystal growth; Physics; A2. Bridgman technique; A1. Morphological stability; 81.05.Bx; B1. Metals; 81.10.Mx; 85.80.Fi; 81.30.Fb; A3. Microgravity conditions; Liquid solid interface; Inorganic compounds; Scattering; Temperature gradients; Dilute alloys; Seebeck effect; Experimental study; Binary alloys; Tin alloys; Morphology; Bismuth alloys; Instability; Microgravity
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2005.01.108

The objective of this paper is to present reference experimental measurements of the morphological stability threshold velocity and cellular growth undercooling for two alloy compositions in the tin–bismuth (Sn–Bi) metallic system. The measure is based on an original in situ diagnostic that relies on the Seebeck thermoelectric effect and benefits from the microgravity environment to guarantee diffusive solute transport conditions. When analysed using independently determined thermo-physical parameters, the experimental data is found to support the validity of the Mullins and Sekerka theory. Above the morphological stability threshold, the data can be interpreted assuming that the cell tips progress along the temperature gradient until the local driving force for morphological instability becomes negligible.