Coexistence of rod-like and lamellar eutectic growth patterns. (15th January 2022)

• Record Type: Journal Article
• Authors: Bottin-Rousseau, Sabine; Witusiewicz, Victor T.; Hecht, Ulrike; Fernandez, Jose; Laveron-Simavilla, Ana; Akamatsu, Silvère
• Is Part Of: Scripta materialia. Number 207(2022)
• Publication Date: 2022-01-15
• Subjects: Eutectic growth -- Directional solidification -- Microgravity -- In situ experimentation; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.114314
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: We present the first observations of a large-scale coexistence between rod-like and lamellar eutectic growth patterns during directional solidification of a eutectic alloy. In situ experiments with real-time optical monitoring were carried out under microgravity onboard the International Space Station (ISS). We used the transparent succinonitrile-d, camphor eutectic alloy that ordinarily forms rod-like patterns. At low growth velocity, short lamellae stabilized at the contact line with a sample glass wall. In the presence of a controlled transverse temperature gradient, the coupled-growth pattern experienced a global drift along an inclined isotherm, and a stable lamellar domain spread over the solidification front. The propagative nature of the lamellar-to-rod transition was evidenced. The advance of the lamellar/rod domain boundary was determined by a slowly amplifying varicose instability of the lamellae. On a large scale, the domain boundary underwent a dynamic faceting. Graphical abstract: Image, graphical abstract