Dissertation > Excellent graduate degree dissertation topics show

Experimental Study of the Static and Dynamic Mechanical Properties of the Ni-Ti Shape Memory Alloy

Author: WangDanDan
Tutor: ZouGuangPing
School: Harbin Engineering University
Course: Engineering Mechanics
Keywords: Ni-Ti shape memory alloy martensitic transformation size effect high strain rate
CLC: TG139.6
Type: Master's thesis
Year: 2008
Downloads: 183
Quote: 1
Read: Download Dissertation


Ni-Ti shape memory alloy (SMA) is a new type of intelligent material, with wide application. Nowadays the research on the mechanical properties of Ni-Ti shape memory alloy is concerned widely. The static and dynamic mechanical properties of SMA are deeply discussed and analyzed in this paper based on previous studies.The mechanical properties of SMA at high strain rate is a hot research area nowadays. At the beginning of this paper, the initial stress of martensitic transformation influenced by the strain rate is investigated, and it shows that the initial stress of martensitic transformation increases with the increasing of strain rate, it is the result of the strain rate strengthen effect. Some different conclusions are gained for the results. The internal temperature of SMA rises when SMA is deformed at the high strain rate, thus leading to the increase of the initial stress of martensitic transformation. At the same time, by comparison with the Ni-Ti SMA under static load, the length along strain of Ni-Ti SMA deformed at high strain rate is relatively small. And when the sample deforms at different high strain rates, the residual strain increases with the increasing of the strain rate, but the deformation recovery rate declines. Repetition impact experiments are also done to present the mechanical properties of the Ni-Ti SMA. The results show that with the increasing of the impact time, not only the initial stress for martensitic transformation increases because of successive strengthen effect, but also the deformation recovery rate increases at the same time.About the static mechanical property of Ni-Ti SMA, the main aim of the job is to study the size effect of the Ni-Ti SMA during the compression process. It is significant to study the size effect for the engineering application, but there is rare research on this aspect. The experiment results show the SMA has a significant size effect in static compression. The main conclusions are as follows. First, during the range of the ratio of height to diameter in this paper, as the ratio increases, the specimen shows harden phenomenon in loading stage and soften phenomenon in unloading stage. Second, parent phase and stress-induced martensitic elasticity modulus also increase. Third, the area surrounded by phase transformation super-elasticity curve increases significantly, it indicates that the capability of energy consumption significantly enhances, that is the capacity of seismatic -resistance and disaster-reduction strengthens obviously when the ratio of height to diameter increases. Also the initial stress for the stress-induced martensitic transformation is piecewise, there exits a certain critical ratio of height to diameter, at which the initial stress for the stress-induced martensitic transformation jumps greatly. When the ratio is lower or higher than the critical value the initial stress for the stress-induced martensitic transformation decreases with the increment of the ratio.

Related Dissertations

  1. Photovoltaic effect on the BaTiO 3 ferroelectric properties of thin films,O484.4
  2. Study of Structures and Performances of Ni51Mn27Ga22 and Ni45Co5Mn36.6In13.4 Ferromagnetic Shape-Memory Alloys and Composites,TG139.6
  3. Study on Size Effect, Bearing Capacity and Residual Pressures of Large Diameter Grouted Pile,TU473.1
  4. Property Research on NiMnGa Magnetic Functional Materials,TG139.6
  5. Discontinuous Galerkin Method of Martensitic Transformation Model,O175.2
  6. Martensitic Transformation in Fe-Ni Nano-particles Prepared by a Sol-gel Process,TB383.1
  7. Martensitic Transformation Crystallography and Finite Element Simulation of Microstructure in Steels,TG142.24
  8. Research on Damping Capacity of CuAlMn Alloy and CuAlMn Reinforced Magnesium Matrix Composites,TB33
  9. Molecular Dynamics Simulations of Vitrification and Martensitic Transformation in Cu-Ti(-Zr) Systems,TQ171.1
  10. Microstructure and Martensitic Transformation of Ga-Mn-Ni-Co Alloys,TG139.6
  11. Micro-Deformation Mechanism of Ti-Ni-Cu Alloy Ribbons,TG146.23
  12. Ni-Mn-Ga ferromagnetic shape memory alloy fiber preparation and the stress -strain behavior of drivers,TG139.6
  13. On the of Acoustic Emission of Martensitic Transformation in CUALNI Alloys,TG139.6
  14. The Recarceh on the Structure, Magentism and Martinstitic Transformation of the Ni-Based Ferromagnetic Shap memory Alloys,TG139.6
  15. The Influnce of Adulteration on the Physical Properties of Ferromagnetic Shape Memory Alloy Mn 2 NiGa,TG139.6
  16. Research on the Phase Transition and Precipitated Carbides of ZG1Cr10MoWVNbN Heat-resistant Steel,TG142.73
  17. Experimental Study of Dynamic Properties of Rubber Concrete,TU528
  18. Necking, Fracture and Critical Impact Velocity in Tension of Oxygen-free High-conductivity Copper Bar,TG115.52
  19. Au-Cu-Al alloy orderly transition of,TG146.21
  20. Phase Transformation and Optical Reflective Properties of Ni-Mn-Ga-Gd Alloy Thin Films,O484.4
  21. Study on the Ferroelectric Transition of Barium Titanate Thin Film by Molecular Dynamics,O484.42

CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > The alloy learn with a variety of properties of alloys > Other special nature of the alloy > Shape Memory Alloys
© 2012 www.DissertationTopic.Net  Mobile