Open AccessINVESTIGATION ON MARTENSITIC TRANSFORMATION AND FIELD-INDUCED TWO-WAY SHAPE MEMORY EFFECT OF Ni-Mn-Ga ALLOY
Author(s) -
柳祝红,
胡凤霞,
王文洪,
陈京兰,
吴光恒,
高书侠,
敖玲
Publication year - 2001
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.50.233
Subject(s) - materials science , shape memory alloy , diffusionless transformation , martensite , thermoelastic damping , curie temperature , condensed matter physics , nucleation , phase boundary , crystallite , alloy , phase (matter) , magnetic shape memory alloy , field (mathematics) , crystallography , thermodynamics , metallurgy , magnetization , microstructure , magnetic field , ferromagnetism , magnetic anisotropy , physics , chemistry , thermal , mathematics , quantum mechanics , pure mathematics
The martensitic phase transformation temperature,Tm and the Curie temperature, TC, of polycrystalline samples Ni2+xMn1-x Ga(x=-0.1,0,0.08,0.13,0.18,0.2) and Ni2-xMn1+x/2Ga1+x/2(x=-0.1,0,0.04,0.06,0.1) have been investigated by measuring the temperature dependence of alternating-current susceptibility. It was found that, with the increase of Ni content,TC decreases and Tm increases for Ni2+xMn1-xGa, and both TC and Tm increase first and decrease afterwards for Ni2-xMn1+x/2Ga1+x/2. Stress-free and two-way thermoelastic shape memory, with 1.2% strain, has been found in single crystal Ni52Mn24Ga24. The deformation can be enhanced more than three times, up to 4.0% shrinkage with a bias field 1.2T applied along the measurement direction. The origin of large recoverable strain should be attributed to the low level of internal stress and the field-induced rearrangement of martensitic variants through twin boundary motion rather than the phase boundary motion.