Magnetorheological fluids

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 d efined 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 Paraffin oil Silicon oil Water Magnetic particles Iron powder Nickel Additives Grease 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. First the required quantity of low viscosity carrier fluid and additives are taken in a beaker mixed thoroughly using a stirrer. 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 . 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