Cooperative strain accommodation over grains in martensitic transformation from Fe-Ni nanocrystalline austenite. (3rd April 2017)

• Record Type: Journal Article
• Authors: Shibata, Akinobu; Ichikawa, Fumitaka; Adachi, Hiroki; Yamasaki, Tohru; Tsuji, Nobuhiro
• Is Part Of: Philosophical magazine letters. Volume 97:Number 4(2017)
• Page Start: 132
• Page End: 139
• Publication Date: 2017-04-03
• Subjects: Martensitic transformations -- nanograined structures -- Fe-based alloys -- transmission electron microscopy -- variant selection; Condensed matter -- Periodicals; Physics -- Periodicals; Solid state physics -- Periodicals; Physique -- Périodiques; 530.41
• DOI: 10.1080/09500839.2017.1292057
• Languages: English
• ISSNs: 0950-0839

Abstract

Abstract: This paper reports an investigation of martensitic transformation behaviour from austenite with various grain sizes ranging from 290 nm to 34 μm in an Fe–Ni alloy fabricated by electrodeposition and subsequent heat treatment. We confirmed that martensite morphology changed from lath to thin plate with decreasing the austenite grain size. Crystallographic orientation analysis revealed that the variants of thin plate martensite formed in the austenite with relatively coarse grains achieved self-accommodation of the transformation strain inside one austenite grain. In contrast, the transformation strain accompanying martensitic transformation from the ultrafine-grained or nanocrystalline austenite was not accommodated by the martensite variants formed in one austenite grain but accommodated cooperatively by those formed in the several adjacent austenite grains.