TY - JOUR

T1 - Mechanical behavior of nanostructured TiNi shape memory alloy with different grain size

AU - Resnina, N.

AU - Belyaev, S.

AU - Pilugin, V.

AU - Glazova, D.

PY - 2017

Y1 - 2017

N2 - An influence of the grain size on the deformation mechanisms of the nanostructured Ti-50,2at.%Ni alloy during tension at two temperatures was studied. The deformation temperatures were chosen as 130 oC at which TiNi phase was in the B2 phase and 25 oC at which the TiNi phase was in R and/or B19’ phase depending on the grain size. The results of the study showed that in austenite B2 phase the nanostructured TiNi alloy was unelastically deformed by dislocation slip and no any pseudoelasticity behaviour was observed. At a temperature of 25 oC the reorientation of the martensite crystals was found before the dislocation slip as it was observed for coarse grain TiNi alloy. Deformation mechanisms observed in the nanostructured Ti-50,2at.%Ni alloy were the same as in coarse grain and a decrease in grain size did not have additional effect to the mechanical behaviour of the samples. It was found that in the samples of the Ti-50,2at.%Ni alloy with a grain sizes of 80 nm and less the dependence of the yield stress on a grain size was described by Hall-Petch law.

AB - An influence of the grain size on the deformation mechanisms of the nanostructured Ti-50,2at.%Ni alloy during tension at two temperatures was studied. The deformation temperatures were chosen as 130 oC at which TiNi phase was in the B2 phase and 25 oC at which the TiNi phase was in R and/or B19’ phase depending on the grain size. The results of the study showed that in austenite B2 phase the nanostructured TiNi alloy was unelastically deformed by dislocation slip and no any pseudoelasticity behaviour was observed. At a temperature of 25 oC the reorientation of the martensite crystals was found before the dislocation slip as it was observed for coarse grain TiNi alloy. Deformation mechanisms observed in the nanostructured Ti-50,2at.%Ni alloy were the same as in coarse grain and a decrease in grain size did not have additional effect to the mechanical behaviour of the samples. It was found that in the samples of the Ti-50,2at.%Ni alloy with a grain sizes of 80 nm and less the dependence of the yield stress on a grain size was described by Hall-Petch law.

U2 - 10.1016/j.matpr.2017.04.081

DO - 10.1016/j.matpr.2017.04.081

M3 - Article

VL - 4

SP - 4841

EP - 4845

JO - Materials Today: Proceedings

JF - Materials Today: Proceedings

SN - 2214-7853

IS - 3PB

ER -