Violation of the sequence of martensite crystals formation on cooling and their shrinking on heating during B2 ↔ B19′ martensitic transformation in Ti40.7Hf9.5Ni44.8Cu5 shape-memory alloy. (4th March 2017)

• Record Type: Journal Article
• Authors: Resnina, Natalia; Belyaev, Sergey; Shelyakov, Alexander; Ubyivovk, Eugeniy
• Is Part Of: Phase transitions. Volume 90:Number 3(2017)
• Page Start: 289
• Page End: 298
• Publication Date: 2017-03-04
• Subjects: Martensite transformations -- shape memory alloys -- in situ electron microscopy -- strain nanodomains; Phase transformations (Statistical physics) -- Periodicals; 530.47405
• DOI: 10.1080/01411594.2016.1180517
• Languages: English
• ISSNs: 0141-1594

Abstract

ABSTRACT: An in situ transmission electron microscopy study of the B2 ↔ B19′ martensitic transformation in Ti40.7 Hf9.5 Ni44.8 Cu5 shape memory alloy was carried out. It was observed that the sequence of the martensite crystals shrinking on heating differed from the sequence of the martensite crystal appearance on previous cooling. This was shown that strain nanodomain formation on cooling prior to the forward martensitic transformation resulted in accumulation of the elastic energy. This led to the dependences of the elastic energy stored on cooling or released on heating on the volume fraction of the martensite phase became different. In this case, at the same volume fraction of the martensite phase, the configuration of the martensite crystals on cooling and heating was different and it was a reason for a violation of the sequence of the martensite crystal formation on cooling and its shrinking on heating.