Introductionto Fsma

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Introductionto Fsma

  1. 1. <ul><li>Nano-Particulate Materials Processing Laboratory </li></ul><ul><li>School of Materials Science and Engineering </li></ul><ul><li>University of Ulsan </li></ul><ul><li>FERROMAGNETIC SHAPE MEMORY ALLOYS ( FSMAs ) </li></ul><ul><li>By </li></ul><ul><li>Nguyen Hoang Viet </li></ul><ul><li>Ryu. Ho-Jin </li></ul>
  2. 2. Contents <ul><li>Introduction to Shape Memory Alloys </li></ul><ul><li>Ferromagnetic SMA </li></ul><ul><li>Application of FSMA </li></ul>
  3. 3. Introduction to Shape Memory Alloys. <ul><li>Shape Memory Alloys (SMAs) are a unique class of metal alloys that can recover apparent permanent strains when they are heated above a certain temperature. </li></ul><ul><li>The SMAs have two stable phases - the high-temperature phase, called austenite and the low-temperature phase, called martensite . In addition, the martensite can be in one of two forms: twinned and detwinned  . A phase transformation which occurs between these two phases upon heating/cooling is the basis for the unique properties of the SMAs. The key effects of SMAs associated with the phase transformation are pseudoelasticity and shape memory effect . </li></ul>
  4. 4. Temperature-induced phase transformation of an SMA without mechanical loading Phase transformation in a NiTi SMA as “seen” by Differential Scanning Calorimeter. M s : Martensite starting temperature M f : Martensite finishing temperature A s : Austenite starting temperature A f : Austenite finishing temperature
  5. 5. Pseudoelasticity <ul><li>The pseudo elastic behavior of SMAs is associated with recovery of the transformation strain upon unloading. The super elastic behavior is observed during loading and unloading above A 0 S and is associated with stress-induced martensite and reversal to austenite upon unloading. </li></ul>
  6. 6. Two phenomena in SMA
  7. 7. SMA Stress Strain Temperature Phase Diagram. Stress vs. Temperature diagram with SMA phases
  8. 8. Contents <ul><li>Introduction to Shape Memory Alloys </li></ul><ul><li>Ferromagnetic SMA </li></ul><ul><li>Application of FSMA </li></ul>
  9. 9. Ferromagnetic SMA Martensitic Alloys “ Natural” SMA Ferromagnetic Alloys The location of magnetic SMAs in the len-shape region formed by the overlap of SMAs and ferromagnetic alloys FSMA candidates: Ni 2 MnGa, Fe-Pd, Fe 3 Pt CoNiAl …
  10. 10. Ferromagnetic SMA (FSMA): background Temperature, External Stress, Magnetic Field Martensitic Transformation Change of Physical Properties and Lattice Parameters (large strain) Shape Memory Effect (SME), Superelasticity (SE) Martensite phase Austenite phase Temperature ( T ) Magnetic Field ( H ) Stress (  )
  11. 11. Possible magnetic field driving mechanisms for FSMA actuators <ul><li>Several driving mechanisms (by magnetic field) of actuators based on FSMAs have been proposed and studied. Three main possible driving mechanisms: </li></ul><ul><li>Magnetic Field Induced Phase Transformation [Direct Effect] </li></ul><ul><li>Variant Rearrangement by Magnetic Field in Fully Martensitic Phase </li></ul><ul><li>Stress Induced Martensitic Transformation by Magnetic Field Gradient [Indirect Effect, Hybrid Mechanism] </li></ul><ul><li>F: Force, </li></ul><ul><li>M: Magnetization, </li></ul><ul><li>H: Magnetic Field </li></ul>
  12. 12. Mechanism of magnetic shape memory <ul><li>(a) (b) (c) </li></ul><ul><li>The shape changes that cause the strokes in </li></ul><ul><ul><li>Conventional magnetostriction, </li></ul></ul><ul><ul><li>Shape memory effect and </li></ul></ul><ul><ul><li>Magnetically driven shape memory materials. </li></ul></ul>
  13. 13. Magnetic field induced redistribution of the twin variants The magnetic moments without the external field The rotation of the magnetic moments within the twins The redistribution of the twin variants A simplified presentation of the MSM effect in a single crystalline actuating element.
  14. 14. Comparisons of magnetic field actuating mechanisms
  15. 15. Contents <ul><li>Introduction to Shape Memory Alloys </li></ul><ul><li>Ferromagnetic SMA </li></ul><ul><li>Application of FSMA </li></ul>
  16. 16. FSMA Actuator Control System The structure of a commonly used MSM actuators. The opposing forces against the MSM element are spring force F spring and external force F ext , while the MSM element itself generates MFI force F mag . The FSMA Actuator Control System
  17. 17. FePd (thin) spring actuator FePd and Fe coil spring (the same size and dimensions) Spring constant: FePd=0.29N/mm, Fe=0.84N/mm (3times)
  18. 18. FSMA Actuator AdaptaMat A063-3 MSM Actutor Actuator A-1 2000 in a tensile test machine. The diameter of the actuator is 260mm and the height 90mm
  19. 19. Linear Motor The actuator can be driven faster/slower (average 70mm/s) and in bigger/smaller steps (accuracy <1μm). http://www.adaptamat.com/demos/
  20. 20. Pump <ul><li>The pump system consists of three parts, the pump itself and two valves. The pump has four chambers. The MSM element empties and fills these chambers in turns. With this procedure it can generate pressure. There are several possibilities how to use the valves and chambers to implement the pump. The pump works in a rotating magnetic field. </li></ul><ul><li>http://www.adaptamat.com/demos/ </li></ul>
  21. 21. Shrinking actuators using a FSMAs material.
  22. 22. References <ul><li>http://www.geocities.com/viet4777/thesis/ </li></ul><ul><li>http://www.fyslab.hut.fi/epm/heusler/ </li></ul><ul><li>http://depts.washington.edu/cims/research/f1.htm </li></ul><ul><li>PERFORMANCE AND MODELING OF MAGNETIC SHAPE MEMORY ACTUATORS AND SENSORS Doctoral Dissertation Ilkka Suorsa </li></ul><ul><li>DETWINNING PROCESS AND ITS ANISOTROPY IN SHAPE MEMORY ALLOYS Yong Liu∗ Smart Materials, 82 Proceedings of SPIE, Vol. 4234 (2001) </li></ul><ul><li>BASIC PROPERTIES OF MAGNETIC SHAPE MEMORY ACTUATORS J. Tellinen, I. Suorsa, A. Jääskeläinen, I. Aaltio and K. Ullakko AdaptaMat Ltd., Helsinki, Finland </li></ul>
  23. 23. <ul><li>Thank you for your attention! </li></ul>

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