On the Mechanism of martensite transformation in near equiatomic NiTi alloy
The martensitic-transformation in polycrystalline Ti-50.3 at pct. Ni alloy has been investigated using the technique of transmission-electron microscopy and diffraction. It was found that the extra reflections observed in the high temperature phase (CsCl, B2 type structure) are not related to the martensitic-transformation but are most likely associated with very fine ordered particles (less than 100A) of a Ni-rich phase, which is coherent with the CsCl-structure. The streaming or shimmering effects observed in bright-field images of a number of alloys which undergo martensitic-transformation and have sometimes been interpreted as a manifestation of lattice oscillations, were not observed in the present investigation. The martensitic-transformation may occur by (110)less than 110 greater than inhomogeneous shear of the CsCl-structure.
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7257150
- Report Number(s):
- LBL-5143
- Country of Publication:
- United States
- Language:
- English
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