1. 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

2. contents Research Objective Project Title Overview
Introduction to Shape Memory Alloy
Nitinol
Rapid Manufacturing using Lasers
Experimental setup
Obtained results
Spring & Parallel Manipulator
CAD model
Analysis using ANSYS
References

3. Research Objective Rapid Manufacturing of Nitinol using Lasers
Deposition of Ni-Ti powder on Ti plate using High power Laser deposition
Manufacturing of a leaf spring
Parallel Manipulator with SMA springs
CAD modeling of the parallel manipulator
Modeling of helical and leaf springs
Analysis using ANSYS
Analyzing the behavior of SMA springs with respect to temperature
Study of the actuation mechanism of SMA springs in 3-DOF parallel manipulator

4. 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

5. APPLICATIONS SMA have applications in industries like-
Medical: Mending bones, Stent in artries, Eyeglass frames, Tooth clips
Military: Nitinol couplers in F-14 fighter planes
Safety:  Anti-scalding devices and fire sprinklers
Robotics: As an actuator

6. NITINOL (Ni-Ti)
Temperature (K)
Young's Modulus (GPa)
294.25
27.17
299.85
24.82
305.35
22.41
310.95
20.06
316.45
25.72
322.05
31.37
327.55
36.96
333.15
42.61
338.75
48.27
344.25
54.88
349.85
61.43
355.35
64.19
360.95
63.16
366.45
62.06
372.05
63.92
377.55
65.78
383.15
67.64
388.75
69.5
394.25
71.36
399.85
70.81
405.35
70.33
410.95
69.78
416.45
69.29
Was discovered in Naval Ordnance Laboratory (NOL), Maryland, USA
Ni- 50% , Ti- 50%
FACT: Even 0.l wt% variation of composition causes 10 K error of transformation temperature.
HIGHLY SENSETIVE TO COMPOSITION!!

7. SME in NiTinol By change in phase from Martensite to Austenite
Monoclinic FCC (Martensite) to BCC (Austenite)

8. 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

9. 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. )

10. Rapid manufacturing using lasers (LRM)
STEP TOWARDS FEATURE BASED DESIGN & MANUFACTURING
EXTENSION OF LASER CLADDING PROCESS
Deposition of a metal on another
Metallurgical bonds are formed
FABRICATION OF PARTS
CAD Model
Powder Material

11. Experimental setup CNC Ti Ni Schematic diagram: Powder Feeder
Ni + Ti powder Ni Ti
Powder Feeder
CNC
High power Laser
5 axes manipulator with CNC control
Argon atmosphere (965 mbar)
No moisture!!
Closed loop process control
Due to diffusion processes in the system, the melting point decreases. Moreover, formation of intermetalic phases, which is usually exothermic, increases temperature of the system. It causes occurrence of eutectic an peritectic systems and melting the batch, which improves homogenization of the system.
Guide Laser
Marking the trajectory
ƛ=605nm
Red color laser
Nozzle
Laser nozzle dia.= 3.29mm
Powder feed nozzle dia.=1.96mm
Deposition
Melting of powder by power laser (IR) ƛ=1080nm
Power of laser= 700W
Deposition mechanism of Ni-Ti powder on Ti plate

12. 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 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

13. 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

14. Spring simulation.avi

18. parallel manupulatorsimulation.avi

22. REFERENCES http://www.stanford.edu/~richlin1/sma/sma.html
Peter R. Barrett, Daniel Fridline. “User Implemented Nitinol Material Model in ANSYS”.
Kaan Divringi & Can Ozcan. “Advanced Shape memory alloy material models for ANSYS”. Ozen Engineering Inc.
Eiji makino, 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: /
Shape Memory Alloy, BTP Report by Saurabh Maghade and Sahil Agarwal.

23. THANK YOU!!
ANY QUESTIONS??