Nanoscale martensitic phase transition at interfaces in shape memory materials

2017 ◽  
Vol 110 (4) ◽  
pp. 041906 ◽  
Author(s):  
Rebecca D. Dar ◽  
Ying Chen
Keyword(s):  
Phase Transition ◽  
Shape Memory ◽  
Martensitic Phase ◽  
Martensitic Phase Transition ◽  
Shape Memory Materials

Study on Crack Tip Field of Shape Memory Alloy Board under Torsion Load

2013 ◽  
Vol 663 ◽  
pp. 397-402
Author(s):  
Bo Zhou ◽  
Tai Yue Yin ◽  
Shi Feng Xue
Keyword(s):  
Phase Transition ◽  
Field Equation ◽  
Shape Memory Alloy ◽  
Stress Field ◽  
Shape Memory ◽  
Crack Tip ◽  
Martensitic Phase ◽  
Mechanical Behaviors ◽  
Crack Tip Field ◽  
Martensitic Phase Transition

This paper focuses on the thermo-mechanical behaviors of the shape memory alloy board with a crack and under the torsion load. A stress field equation from mechanics of elasticity is used to describe the stress distribution around the crack tip in the shape memory alloy board. A martensitic phase transition equation is supposed to predict the martensitic phase transition behaviors of the field near the crack tip in the shape memory alloy board. The martensitic phase transition zones near the crack tip in the shape memory alloy board under the torsion load are numerically described based on the stress field equation and martensitic phase transition equation at various temperatures. Results show that the stress field equation and martensitic phase transition equation can predict the thermo-mechanical behaviors of the shape memory alloy board with a crack and under the torsion load effectively.

The Interior of the Pseudoelastic Hysteresis

1991 ◽  
Vol 246 ◽  
Author(s):  
Senlin Fu ◽  
Ingo Müller ◽  
Huibin Xu
Keyword(s):  
Phase Transition ◽  
Phase Equilibrium ◽  
Shape Memory ◽  
Hysteresis Loop ◽  
Martensitic Phase ◽  
Interesting Problem ◽  
Elastic Hysteresis ◽  
Martensitic Phase Transition ◽  
Unstable Phase

AbstractAn interesting problem within the research on shape memory is provided by the investigation of the pseudo-elastic hysteresis loop that accompanies the strain-induced austenitic-martensitic phase transition. Miller [1] suggested by thermodynamic arguments that the size of that loop should be related to the coherency energy at interfaces between martensite and austenite. That proposition received a boost when Müller & Xu [2] showed that the same thermodynamic arguments predicted the onset of internal yield and recovery inside the hysteresis loop on a well-definqd line of unstable phase equilibrium. Recently Fu, Müller and Xu [3] have reported results with improved specimens and methods of observation that may help to understand the nature of metastability inside the hysteresis loop.

Effect of high magnetic field on the two-step martensitic-phase transition in Ni2MnGa

2000 ◽  
Vol 76 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Yanwei Ma ◽  
S. Awaji ◽  
K. Watanabe ◽  
M. Matsumoto ◽  
N. Kobayashi
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
High Magnetic Field ◽  
Martensitic Phase ◽  
Martensitic Phase Transition

scholarly journals Phase Transition in Iron Thin Films Containing Coherent Twin Boundaries: A Molecular Dynamics Approach

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3631 ◽  
Author(s):  
Binjun Wang ◽  
Yunqiang Jiang ◽  
Chun Xu
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Molecular Dynamics ◽  
Free Surface ◽  
Transition Temperature ◽  
Film Thickness ◽  
Martensitic Phase ◽  
Martensitic Transition ◽  
Twin Boundaries ◽  
Martensitic Phase Transition

Using molecular dynamics (MD) simulation, the austenitic and martensitic phase transitions in pure iron (Fe) thin films containing coherent twin boundaries (TBs) have been studied. Twelve thin films with various crystalline structures, thicknesses and TB fractions were investigated to study the roles of the free surface and TB in the phase transition. In the austenitic phase transition, the new phase nucleates mainly at the (112)bcc TB in the thicker films. The (111¯)bcc free surface only attends to the nucleation, when the film is extremely thin. The austenitic transition temperature shows weak dependence on the film thickness in thicker films, while an obvious transition temperature decrease is found in a thinner film. TB fraction has only slight influence on the austenitic temperature. In the martensitic phase transition, both the (1¯10)fcc free surface and (111)fcc TB attribute to the new body-center-cubic (bcc) phase nucleation. The martensitic transition temperature increases with decreased film thickness and TB fraction does not influent the transition temperature. In addition, the transition pathways were analyzed. The austenitic transition obeys the Burgers pathway while both the Kurdjumov–Sachs (K–S) and Nishiyama–Wassermann (N–W) relationship are observed in the martensitic phase transition. This work may help to understand the mechanism of phase transition in the Fe nanoscaled system containing a pre-existing defect.

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