Microstructure in the cubic to monoclinic transition in titanium-nickel shape memory alloys
- Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Aerospace Engineering and Mechanics
Microstructure in the cubic to monoclinic transition in the technologically important Ti-Ni shape memory alloys is considered. Using a geometrically nonlinear theory of martensitic transformations, the twinned martensite, austenite-martensite, wedge, triangle, and diamond microstructures are studied. Specifically, compound, type 1, and type 2 twins are possible for any choice of the lattice parameters; while, non-standard twins may exist with special lattice parameters only. In addition, 192 habit planes are found for a particular Ti-Ni alloy, but only 24 have been unambiguously observed in experiments. Further, the twinned wedge is possible in this alloy, but the triangle and diamond are not. These latter three are special microstructures, which provide a mechanism through which a specimen can easily transform and are possible only for alloys with specific lattice parameters. A complete enumeration of the various microstructures is given, and algorithms are presented so that the calculations can be repeated with different lattice parameters.
- OSTI ID:
- 6450000
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Vol. 47:9; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microstructures, Martensitic Transformation, and Mechanical Behavior of Rapidly Solidified Ti-Ni-Hf and Ti-Ni-Si Shape Memory Alloys
On the lattice parameters of phases in binary Ti-Ni shape memory alloys
Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
ALGORITHMS
ALLOYS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CUBIC LATTICES
LATTICE PARAMETERS
MATHEMATICAL LOGIC
MICROSTRUCTURE
MONOCLINIC LATTICES
NICKEL ALLOYS
PHASE TRANSFORMATIONS
SHAPE MEMORY EFFECT
TITANIUM ALLOYS