Stress-induced martensitic phase transformation in thin sheets of Nitinol

Using the in situ optical technique known as digital image correlation (DIC), full-field quantitative strain maps of localization have been experimentally obtained for the first time in thin sheets of Nitinol. The use of DIC provides new information connecting previous observations on the micro- and macro-scales. It shows that the transformation initiates before the formation of localized bands, and the strain inside the bands does not saturate when they nucleate. The effect of rolling texture on the macroscopic stress–strain behavior was observed and it is shown that the resolved stress criterion or Clausius–Clapeyron relation does not hold for polycrystalline Nitinol. Finally, the effect of geometric defects on localization behavior was observed.

[1]  Robert V. Kohn,et al.  Symmetry, texture and the recoverable strain of shape-memory polycrystals , 1996 .

[2]  P. Feng,et al.  Experimental investigation on macroscopic domain formation and evolution in polycrystalline NiTi microtubing under mechanical force , 2006 .

[3]  K. Bhattacharya,et al.  THE INFLUENCE OF TEXTURE ON THE SHAPE- MEMORY EFFECT IN POLYCRYSTALS , 1998 .

[4]  V. Novák,et al.  On the origin of Luders-like deformation of NiTi shape memory alloys , 2005 .

[5]  H. Tobushi,et al.  Thermomechanical investigations of martensitic and reverse transformations in TiNi shape memory alloy , 2004 .

[6]  J. Anderegg,et al.  Surface conditions of Nitinol wires, tubing, and as-cast alloys. The effect of chemical etching, aging in boiling water, and heat treatment. , 2003, Journal of biomedical materials research. Part B, Applied biomaterials.

[7]  W. H. Peters,et al.  Application of an optimized digital correlation method to planar deformation analysis , 1986, Image Vis. Comput..

[8]  K. Bhattacharya.  Microstructure of martensite : why it forms and how it gives rise to the shape-memory effect , 2003 .

[9]  C. M. Wayman,et al.  Shape-Memory Materials , 2018 .

[10]  V. Novák,et al.  A network micromechanics model of thermomechanical behaviors of SMA polycrystals , 2004 .

[11]  Petr Šittner,et al.  Anisotropy of martensitic transformations in modeling of shape memory alloy polycrystals , 2000 .

[12]  J. Shaw,et al.  Thermomechanical aspects of NiTi , 1995 .

[13]  K. Ravi-Chandar,et al.  Dynamics of propagating phase boundaries in NiTi , 2006 .

[14]  Rolf Lammering,et al.  Stress-induced transformation behavior of a polycrystalline NiTi shape memory alloy: micro and macromechanical investigations via in situ optical microscopy , 2004 .

[15]  H. D. Chopra,et al.  Domain structures in bent In-22.5 at.%Tl polydomain crystals , 1996 .

[16]  T. Shield.  Orientation dependence of the pseudoelastic behavior of single crystals of CuAlNi in tension , 1995 .

[17]  Perry H Leo,et al.  Transient heat transfer effects on the pseudoelastic behavior of shape-memory wires , 1993 .

[18]  C. Somsen,et al.  Investigation of the phase evolution in a super-elastic NiTi shape memory alloy (50.7 at.%Ni) under extensional load with synchrotron radiation , 2004 .

[19]  S. Miyazaki,et al.  Shape memory effect and pseudoelasticity in a TiNi single crystal , 1983 .