Three-dimensional in situ characterization of phase transformation\n induced austenite grain refinement in nickel-titanium

2018/10/14 by Ashley Bucsek, Lee Casalena, Bucsek, Ashley N. +11
Engineering · Materials Science · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Microstructure and Mechanical Properties of Steels #Microstructure and mechanical properties #Shape Memory Alloy Transformations

paper · pdf · doi:10.48550/arxiv.1810.06141

openalex publication_date 2018/10/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Near-field and far-field high-energy diffraction microscopy and microcomputed\ntomography X-ray techniques were used to study a bulk single crystal\nnickel-titanium shape memory alloy sample subjected to thermal cycling under a\nconstant applied load. Three-dimensional in situ reconstructions of the\naustenite microstructure are presented, including the structure and\ndistribution of emergent grain boundaries. After one cycle, the subgrain\nstructure is significantly refined, and heterogeneous \Σ3 and \Σ9\ngrain boundaries emerge. The low volume and uneven dispersion of the emergent\n\Σ boundaries across the volume show why previous transmission electron\nmicroscopy investigations of \Σ grain boundary formation were\ninconsistent.\n

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