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SHAPE MEMORY ALLOY. I.i.t . Indore . R.r.c.a.t . indore. Under the guidance of : DR. I.A. Palani Dr. C.p . Paul. Presented by: Sandesh Dhurve Nishchay Sharma. contents. Research Objective. Shape Memory Alloy. It remembers its shape Deformed shape + Heat = Original shape
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SHAPE MEMORY ALLOY I.i.t. Indore R.r.c.a.t. indore Under the guidance of: DR. I.A. Palani Dr. C.p. Paul Presented by: SandeshDhurve Nishchay Sharma
Shape Memory Alloy • It remembers its shape • Deformed shape + Heat = Original shape • The high temperature causes the atoms to arrange themselves into the most compact and regular pattern possible • Example: Copper-Aluminum-Nickel, Copper-Zinc-Aluminum, Iron- Manganese-Silicon and Nickel-Titanium alloys
APPLICATIONS Medical: Mending bones, Stent in artries, Eyeglass frames, Tooth clips • SMA have applications in industries like- Military: Nitinol couplers in F-14 fighter planes Safety: Anti-scalding devices and fire sprinklers Robotics: As an actuator
NITINOL (Ni-Ti) • Was discovered in Naval Ordnance Laboratory (NOL), Maryland, USA • Ni- 50% , Ti- 50% FACT: Even0.l wt% variation of composition causes 10 K error of transformation temperature. HIGHLY SENSETIVE TO COMPOSITION!!
SME in NiTinol • By change in phase from Martensite to Austenite • Monoclinic FCC (Martensite) to BCC (Austenite)
ADVANTAGES • Compactness, allowing for reduction in overall actuator size. • Very high power/weight ratio comparatively • Accessible voltages can accomplish thermo elastic transformation • Higher strain recovery • Higher strength • Noiseless and silent operation • High corrosion resistance
LIMITATIONS • Heat Dissipation, need Mechanism for cooling • Less Stiffness / high Flexibility • Relatively expensive to manufacture and machine compared to other materials such as steel and aluminum. • Most SMA's have poor fatigue properties ( a steel component may survive for more than one hundred time more cycles than an SMA element. )
Experimental setup Schematic diagram: Powder Feeder Closed loop process control Deposition mechanism of Ni-Ti powder on Ti plate
POWER LASER SPECIFICATIONS • ƛ=1080nm (IR laser); feed= 4gm/min • Ytterbium laser system YLS-2000 • A coolant is used for cooling the nozzle. • Temperature of nozzle is kept around 21-22 C • Maximum power of the laser= 2000W • Power during process= 700W Power of the laser is adjusted to get proper penetration, melting and deposition. Less power causes poor melting and high power causes sputtering!! LRM based CNC Machine
Modeling & Simulation Helical spring Diameter of spring…………………..D = 1.5mm Wire diameter………………………..d = 0.5 mm Number of turns……………………..n = 40 Length of fully compressed spring….L= 20 mm Leaf spring Rectangular cross section…………..w = 5mm h = 5mm Arc radius…………………………..r = 37.5 mm Parallel manipulator with helical spring Parallel manipulator with leaf spring
REFERENCES • http://www.stanford.edu/~richlin1/sma/sma.html • www.wikipedia.org • Peter R. Barrett, Daniel Fridline. “User Implemented Nitinol Material Model in ANSYS”. • KaanDivringi & Can Ozcan. “Advanced Shape memory alloy material models for ANSYS”. Ozen Engineering Inc. • Eijimakino, Takashi Mitsuya, Takayuki Shibata. “ Fabrication of TiNi shape memory actuator for micropump”. Proc. SPIE 3891, Electronics and Structures for MEMS, 328 (September 29, 1999); doi:10.1117/12.364458 • Shape Memory Alloy, BTP Report by SaurabhMaghade and SahilAgarwal.
THANK YOU!! ANY QUESTIONS??