Morphological stability of a binary alloy: thermodiffusion and temperature-dependent diffusivity

• Published in: Journal of crystal growth Vol. 223; no. 4; pp. 565 - 572
• Main Authors: Van Vaerenbergh, S., Coriell, S.R., McFadden, G.B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2001; Elsevier
• Subjects: A1. Diffusion; A1. Morphological stability; A1. Solidification; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Metals. Metallurgy; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Solid-fluid interfaces; Solidification; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); A1. Morphological stability; 66.10.Cb; 64.70.Dv; A1. Diffusion; A1. Solidification; 81.10.Fq; 81.30.Fb; Soret effect; Liquid solid interface; Directional solidification; Digital simulation; Growth interface; Thermodiffusion; Binary alloys; Tin alloys; Morphology; Heat mass transfer; Linear stability; Diffusion coefficient; Silver alloys; Transition element alloys
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(01)00620-0

The effect of a temperature-dependent solute diffusion coefficient on the morphological stability of a binary alloy during directional solidification is treated by a linear stability analysis. The Soret effect (thermodiffusion) is also included in the analysis. Specific calculations are carried out for a tin alloy containing silver for which the diffusion coefficient has a linear dependence on temperature. Although the temperature dependence of the diffusion coefficient has little effect on the critical concentration for the onset of morphological stability, it causes a significant change in the wavelength at the onset of instability.