SMART FLUIDS CALLED MR FLUIDS HAVE APPLICATIONS IN MR DAMPER, MR FINISHING PROCESSES

1. SMART MATERIALS : MAGNETORHEOLOGICAL FLUIDS
DONE BY:
GIRISH RAGHUNATHAN
1
Rashtriya Shiksha Samithi Trust, Bengaluru-560059
RV College of Engineering
M.Tech in Machine Design
PHYSICS OF MATERIALS
ASSIGNMENT 18PHY2G09
on
UNDER THE GUIDANCE OF : Dr.G Shireesha
04-07-2019

2. OUTLINE
• INTRODUCTION
• OPERATING PRINCIPLE AND MODES
• FLOW BEHAVIOUR
• CONSTITUENTS AND PREPARATION OF MR FLUIDS
• APPLICATIONS
• REFERENCES
04-07-2019 2

3. INTRODUCTION
• Smart Materials are defined as materials that possess ability to change
their physical properties in a specific manner in response to specific
stimulus input. Are capable of sensing and actuating with quick
controllable response.
• Inputs may be heat, magnetic /electric field, light, pressure etc.
• The output may be change in shape, stiffness, current, voltage, viscosity,
conductivity etc.
• Examples of Smart materials are Piezoelectric crystals, shape memory
alloys, electrorheological fluids, magnetorheological fluids etc.
04-07-2019 3

4. INTRODUCTION
• Magnetorheological fluid (MR Fluid) is a smart fluid that is field responsive and
is capable of changing its rheological properties on application of magnetic
field.
• MR fluid is a free-flowing liquid in the absence of a magnetic field while its
viscosity increases on application of magnetic field.
04-07-2019 4
Fig. 1. Magnetorheological fluid. a) Before magnetization b) After Magnetization

5. Working Principle
• MR fluid is a smart fluid whose properties can be controlled in the presence of magnetic
field.
• In the absence of magnetic field the MR fluid behaves like a Newtonian fluid and has
nearly the same characteristics as the carrier or base fluid.
Fig. 2. Without the presence of magnetic field
04-07-2019 5

6. • In the presence of magnetic field, the microscopic particles align themselves along the lines of
magnetic flux.
• A chain like structure is formed along the line of magnetic flux which offers mechanical
resistance to the flow resulting in an increase in the viscosity of fluid.
Fig. 3 With the magnetic field
04-07-2019 6

7. Operating modes
04-07-2019 7
Fig. 5 Operating modes of MR Fluids

8. FLOW BEHAVIOUR
Fig.6 Flow behaviour of
Newtonian and Bingham Plastic
liquids
04-07-2019 8
Fig.7 Velocity profile of MR fluid

9. CONSTITUENTS OF MR FLUID
• Carrier oil
1. Paraffin oil
2. Silicon oil
3. Water
• Magnetic particles
1. Iron powder
2. Nickel
Additives
1. Grease
2. Arabic gum
04-07-2019 9
CARBONYL IRON SILICONE OIL STEARIC ACID GUAR GUM
20 - 30 % 70 % - 80 % 0.5 % - 1.5 % 0.5 % - 1.5 %
Table 1 : Composition of MRF in volume fraction (%)

10. Fig 8: Silicone oil Fig 9: Stearic acid Fig 10: guar gum
Fig 11: Carbonyl iron particles
04-07-2019 10
CONSTITUENTS OF MR FLUID

11. PREPARATION OF MR FLUID
• Following are the steps for preparation of MR fluid.
1. First the required quantity of low viscosity carrier fluid and additives are taken in a beaker
mixed thoroughly using a stirrer.
2. After that iron particles of about 50 micron size are added to the above mixture and again
stirred well with the help of stirrer for a duration of 24 hours .
3. The preparation is termed fine if the particles do not sediment after leaving the solution
undisturbed for some time.
04-07-2019 11

12. PROPERTIES OF MR FLUIDS
04-07-2019 12
Table 2 General Properties of MR FLuid

13. ADVANTAGES & LIMITATIONS
• Advantages:
• Semi active control is possible.
• Easy to control.
• Quick response and stable.
• Disadvantages:
• High quality fluids are expensive.
• Subjected to thickening after prolonged use and needs replacing.
• Settling of Ferro-particles can be a problem for some application.
04-07-2019 13

14. APPLICATIONS
04-07-2019 14

15. 1. Magnetorheological finishing
04-07-2019 15
Fig.12 Schematic of Magnetorheological finishing process

16. 04-07-2019 16
Fig.13 Forces acting on abrasive particles

17. 04-07-2019 17
Fig.14 Arrangement of CIP’s and abrasive particles

18. 04-07-2019 18
Fig.15 Variation of normal and tangential force with CIP
concentration and working gap
Fig.16 Variation of normal and tangential force with
abrasive concentration

19. 04-07-2019 19
Fig.17 Variation of normal and tangential force with wheel
speed (rpm)

20. 04-07-2019 20
Fig.18 Applications of Magnetorheological finishing process

21. 2. Magneto rheological damper
Fig. 19 MR damper in shear mode
04-07-2019 21

22. REFERENCES
• J. D. Carlson and M. R. Jolly, Mechatronics 10, 555 350 (2000).
• M. R. Jolly, J. W. Bender, and J. D. Carlson, J. Intel. 356 Mat. Syst. Str. 10, 5 (1999).
• Grezegorz Slowinski, Tadevz Niezgod, Damuta Miedzinska Roman Gieleta, 2010, “Influence of volume fraction
of carbonyl iron particles on the mechanical properties of the magnetorheological elastomers”, Journal of
KONES Powertrain and Transport, Vol. 17, No. 3
• MUHAMMAD Aslam., YAO Xiong-liang., and DENG Zhong-Chao., September 2006, “Review of
Magnetorheological (MR) Fluids and its Applications in vibration control”, Journal of Marine Science and
Application, Vol.5, No.3, PP:17-29.
• Suryawanshi Ravishankar, Rayappa Mahale, “A study on magneto rheological fluids and their applications”,
International Research Journal of Engineering and Technology (IRJET), Volume: 02 Issue: 04, July-2015.
• Jain, V.K., (2009), “Magnetic field assisted abrasive based micro-/nanofinishing”,Journal of Materials
Processing Technology, Vol. 209, 6022–6038.
• Wang, A.C., Tsai, L., Liu, C.H., Liang, K.Z., and Lee, S.J., (2011),“Elucidating the Optimal Parameters in
Magnetic Finishing with Gel Abrasive”, Materials and Manufacturing Processes, Vol. 26, No.5, 786-791
04-07-2019 22

23. Thank You