On/off directional solidification of near peritectic TRIS-NPG with a planar but tilted solid/liquid interface under microgravity conditions. (June 2022)

• Record Type: Journal Article
• Authors: Ludwig, Andreas; Mogeritsch, Johann; Rettenmayr, Markus
• Is Part Of: Scripta materialia. Number 214(2022)
• Publication Date: 2022-06
• Subjects: Bridgman technique -- Directional solidification -- Optical microscopy -- Interface segregation -- Peritectic alloy; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2022.114683
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Understanding phenomena that occur during gradient annealing and initial transient of Bridgman-type directional solidification processes is essential for producing high-performance materials with specific properties. An experiment with alternating long time gradient annealing and directional solidification periods was performed on the International Space Station, using a near-peritectic transparent TRIS-NPG alloy. It transpired that accumulation of solute ahead of the solid/liquid interface continued to progress and that steady-state growth conditions were never achieved. The results demonstrate that (i) liquid being squeezed out from the mush during the long time gradient annealing period disables the formation of a flat interface; (ii) a thermal bias caused a slightly tilted planar solidification front; and (iii) growth of the metastable pro-peritectic α-phase led to the formation of a supersaturated solid that solidified with an intriguing low growth rate. Graphical abstract: Image, graphical abstract