Experimental evidence of stress-field-induced selection of variants in Ni-Mn-Ga ferromagnetic shape-memory alloys

Journal Article · Tue May 01 04:00:00 EDT 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.75.174404· OSTI ID:20957833

Wang, Y D ^[1]; Brown, D W ^[2]; Choo, H; Liaw, P K; Benson, M L ^[1]; Cong, D Y; Zuo, L ^[3]

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1. Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)
2. Los Alamos Neutron Scattering Center, Los Alamos National Laboratory, New Mexico 87545 (United States)
3. Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China)

The in situ time-of-flight neutron-diffraction measurements captured well the martensitic transformation behavior of the Ni-Mn-Ga ferromagnetic shape-memory alloys under uniaxial stress fields. We found that a small uniaxial stress applied during phase transformation dramatically disturbed the distribution of variants in the product phase. The observed changes in the distributions of variants may be explained by considering the role of the minimum distortion energy of the Bain transformation in the effective partition among the variants belonging to the same orientation of parent phase. It was also found that transformation kinetics under various stress fields follows the scale law. The present investigations provide the fundamental approach for scaling the evolution of microstructures in martensitic transitions, which is of general interest to the condensed matter community.

• OSTI ID: 20957833
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 17 Vol. 75; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTAL STRUCTURE
FERROMAGNETIC MATERIALS
GALLIUM ALLOYS
MANGANESE ALLOYS
MICROSTRUCTURE
NEUTRON DIFFRACTION
NICKEL ALLOYS
PHASE TRANSFORMATIONS
SHAPE MEMORY EFFECT
STRESSES
TIME-OF-FLIGHT METHOD
TRANSFORMATIONS