Stress-induced martensitic transformation and microstructure of a Ti36Ni49Hf15 high-temperature shape-memory alloy

L. H. Liu, X. L. Meng, W. Cai, Y. F. Zheng, Y. X. Tong, L. C. Zhao, Li Min Zhou

Research output: Journal article publicationConference articleAcademic researchpeer-review

Abstract

The stress-induced martensitic transformation behavior and the microstructure of stress-induced martensite (SIM) in a Ti36Ni49Hf15 high temperature shape memory alloy (SMA) have been investigated using tensile tests and transmission electron microscopy (TEM) in this paper. It shows that, compared with TiNi SMAs, there is no stress plateau in the stress-strain (S-S) curve as the TiNiHf alloy deformed in austenite. The martensitic transformation enthalpy is calculated to be - 106.84cal/mol. The martensite variants mainly show preferential oriented morphologies for the TiNiHf alloy deformed to 8% at 523k. The substructure of SIM and deformed SIM in the present alloy is (001) compound twin. Martensite variants are (011) type I twin related. Further increasing the deformation temperature and strain, the preferential oriented SIMs gradually develop to martensite variants with variant-crashed / variant-intersected morphologies. The inexistence of stress plateau in the S-S curve of the TiNiHf alloy may mainly result from the dislocation slip during stress-induced martensitic transformation.
Original languageEnglish
Pages (from-to)447-450
Number of pages4
JournalMaterials Science Forum
Volume394-395
Publication statusPublished - 2 Dec 2002
Externally publishedYes
EventProceedings of the International Conference on Shape Memory and Superelastic Technologies and Shape Memory Materials (SMST-SMM 2001) - Kumning, China
Duration: 2 Sep 20016 Sep 2001

Keywords

  • High-Temperature Shape-Memory Alloy
  • Microstructure
  • Stress-Induced Martensitic Transformation
  • TiNiHf Alloy

ASJC Scopus subject areas

  • Materials Science(all)

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