Stress-induced α″ phase in a beta Ti–19Nb–1.5Mo–4Zr–8Sn alloy
- School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China)
- BAOTI Group Ltd., Baoji, Shanxi 721014 (China)
Highlights: • Morphologies/distributions of α″ produced by stretching/rolling are similar. • Under small deformation, α″ martensite consists of parallel lamellar structures. • Under larger deformations, martensite has ladder-like pattern and parallel ellipsoids. • With the increase of deformation hardness decreases firstly and then increases. - Abstract: The morphological evolution of the stress-induced α″ martensite with increases in the stretching and rolling deformation degrees as well as the related orientation relationship were investigated in a β titanium alloy (Ti–19Nb–1.5Mo–4Zr–8Sn)·For a stretching deformation of 1%, the α″ martensite exhibited a packet morphology consisting of parallel lamellar structures. On the other hand, in the 2%-rolled sample, the α″ martensite exhibited a long lath-like distribution, which was accompanied by a few small pieces. With an increase in the deformation degree, the α″ martensite gradually exhibited a ladder-like structure consisting of long and short α″ laths or ellipsoids. The existence of these self-accommodating martensitic variants decreased the elastic energy. The parallel α″ laths present within a single packet were found to have the same orientation. The interface between the α″ and β phases was coherent, and their lattice constant relationships were identified as √2a{sub β}≈b{sub α″}≈c{sub α″} and a{sub β} ≈ a{sub α″}. Further, with the increase in the deformation degree, the hardness of the alloy first decreased and then increased; this was the case both the stretched as well as the rolled samples.
- OSTI ID:
- 22805746
- Journal Information:
- Materials Characterization, Vol. 140; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
Similar Records
Crystallographic Features of the α-Phase Structure in Hafnium and Hafnium–Titanium Alloys
Characteristics of martensite transformed from deformed austenite with various states of ultrahigh strength 300 M steel