TY - JOUR
T1 - Increasing magnetoplasticity in polycrystalline Ni-Mn-Ga by reducing internal constraints through porosity
AU - Boonyongmaneerat, Yuttanant
AU - Chmielus, Markus
AU - Dunand, David C.
AU - Müllner, Peter
PY - 2007/12/10
Y1 - 2007/12/10
N2 - Foams with 55% and 76% open porosity were produced from a Ni-Mn-Ga magnetic shape-memory alloy by replication casting. These polycrystalline martensitic foams display a fully reversible magnetic-field-induced strain of up to 0.115% without bias stress, which is about 50 times larger than nonporous, fine-grained Ni-Mn-Ga. This very large improvement is attributed to the bamboolike structure of grains in the foam struts which, due to reduced internal constraints, deform by magnetic-field-induced twinning more easily than equiaxed grains in nonporous Ni-Mn-Ga.
AB - Foams with 55% and 76% open porosity were produced from a Ni-Mn-Ga magnetic shape-memory alloy by replication casting. These polycrystalline martensitic foams display a fully reversible magnetic-field-induced strain of up to 0.115% without bias stress, which is about 50 times larger than nonporous, fine-grained Ni-Mn-Ga. This very large improvement is attributed to the bamboolike structure of grains in the foam struts which, due to reduced internal constraints, deform by magnetic-field-induced twinning more easily than equiaxed grains in nonporous Ni-Mn-Ga.
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U2 - 10.1103/PhysRevLett.99.247201
DO - 10.1103/PhysRevLett.99.247201
M3 - Article
C2 - 18233476
AN - SCOPUS:36949015389
SN - 0031-9007
VL - 99
JO - Physical review letters
JF - Physical review letters
IS - 24
M1 - 247201
ER -