Direct evidence of detwinning in polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloys during deformation.

Journal Article · Tue Jan 01 00:00:00 EST 2008 · J. Appl. Phys.

DOI:https://doi.org/10.1063/1.3020534· OSTI ID:951254

Nie, Z H; Lin Peng, R; Johansson, S; Oliver, E C; Ren, Y; Wang, Y D; Liu, Y D; Deng, J N; Zuo, L; Brown, D E

In situ time-of-flight neutron diffraction and high-energy x-ray diffraction techniques were used to reveal the preferred reselection of martensite variants through a detwinning process in polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloys under uniaxial compressive stress. The variant reorientation via detwinning during loading can be explained by considering the influence of external stress on the grain/variant orientation-dependent distortion energy. These direct observations of detwinning provide a good understanding of the deformation mechanisms in shape memory alloys.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Natural Science Foundation of China (NSFC); Swedish Research Council (SRC); Ministry of Education of China
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 951254
• Report Number(s): ANL/XSD/JA-63624; JAPIAU; TRN: US200911%%403
• Journal Information: J. Appl. Phys., Vol. 104, Issue 2008; ISSN 0021-8979
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
NICKEL ALLOYS
MANGANESE ALLOYS
GALLIUM ALLOYS
SHAPE MEMORY EFFECT
TWINNING
DEFORMATION
MARTENSITE
MORPHOLOGICAL CHANGES