The document discusses 3D surface finishing using magnetorheological finishing. It begins with an introduction to the demand for high quality surface finishes and limitations of traditional processes. It then discusses the experimental setup developed at IIT Delhi which uses a magnetorheological fluid and external magnetic field to provide nano-level surface finishes. The objectives are to integrate a 4th axis of rotation to enable finishing of inclined surfaces and verify improved results. Experimentation was conducted on flat, inclined, and curved surfaces both with and without the 4th axis, showing significantly better uniformity of finish when using the additional rotational axis.

1. 3D Surface Finishing Using
Magnetorheological Finishing
Under the guidance of
Dr. Sunil Jha
Presented by
Amitesh kumar
(2010MEP2968)

2. CONTENTS
• Introduction
• Literature Review
• Experimental Setup
• Motivation and Objective
• 4th axis integration
• Experimentation
• Results and conclusion
• Scope of future work
• References

3. Introduction
• Huge demand of good surface finish in different industries
specially automotive, aerospace, mold manufacturing etc.
• All traditional finishing processes are incapable of producing
required surface finish of nanometer level for these industries.
• A number of processes like Abrasive Flow Machining (AFM),
Magnetic Abrasive finishing (MAF), Magnetic Float Polishing
(MFP) etc. have been developed.
• Magnetorheological (MR) finishing is one of the processes
which can provide surface finish up to nano meter level

4. MR Fluid
Constituent % volume concentration
Carbonyl iron powder 20
Silicon carbide 20
Base fluid medium 60
 Changes in rheological behaviour in presence of external
magnetic field.
 Iron particles acquire dipole moment in presence of magnetic
field and is proportional to field strength.

5. (a) Abrasives & Carbonyl iron particles at zero magnetic fields
(b) Abrasive particles embedded in Carbonyl iron particle
chains on application of external magnetic field [2]

6. No finishing action in absence of external magnetic field [2]
Finishing action on a single profile in presence of external magnetic field[2]

7. Literature Review
• Design and development of Magnetorheological Abrasive flow
finishing process by S. Jha and V. K. Jain (2004)
• It was observed that chain formation takes place in
magnetorheological fluid on application of external magnetic
force.
• It was also observed that surface roughness reduces with
increase in magnetic field.
Change in rheological behaviour of MR fluid during finishing [2]

8. • Seok et al. (2008) [3] has proposed magnetorheological
finishing process for hard materials using sintered iron-CNT
compound abrasives.
• It was observed that material removal rate increases with
rotational speed of tool upto a certain critical value (500 rpm)
and decreases for speed beyond this critical value.
• It was also observed that if the rotation speed of tool is
increased to increase the material removal rate, the centrifugal
force acting on CI particle plays an adverse role.

9. • A. Sidpara & V. K. Jain (2010) [4] investigated the role of
different parameters on force.
• It was observed that the contribution of working gap on forces
developed was observed maximum followed by CIP
concentration while the least contribution was observed for
rotating speed.

10. Experimental setup at IITD
Schematic of existing setup installed at IIT DELHI[1]

12. Electromagnetic model of MR finishing tool [1]

13. Shape of magnetic flux density generated at the MR finishing tool [1]

14. Magnetic flux density at the interface between MR fluid and work surface [1]

15. Motivation and Objective
• For an inclined surface, the outer surface of the MR fluid
touches the work surface where the magnetic field intensity is
very less as compared to centre.

16. No of Ra (nm) Ra(nm) Ra(nm) of Ra(nm)
finishing of flat of 30 45 surface of curve
passes surface surface surface
0 1334.1 1452.3 2739.3 1754.7
15 812.3 1296.1 1949.4 1513.2
% improvement 39.13 10.74 28.84 13.74
in finish

17. Objective
• Integration of rotary axis on to machine for tool tilting.
• Experimentation on 3D MRF Machine for verification of
improvement in surface finish

18. 4th axis integration
To give the 4th axis motion to the existing setup, these
components are being used:
 Rotation stage
 Stepper motor
 Stepper drive

19. MRS series Holmarc rotation stage Tool post to be mount on rotation stage
Stepper drive
Stepper motor

20. Rotation control of rotary stage by computer

21. Rotary stage with stepper motor mounted on vertical slider

22. Proposed setup after integration of 4th axis

23. Perpendicular angle between tool and workpiece after 4th axis
integration

24. Experimentation
• Preparation of workpiece
• Fluid preparation
• Surface finishing with MR fluid
• Motion control with the help of software
• Measurement of surface finish using Taylor Hobson Talysurf

25. Preparation of workpiece

26. Fluid preparation
Constituent Density (gm/cm³)
Base fluid 0.638
CIP 7.8
SiC 3.22
Densities of MR fluid constituents
Carbonyl iron powder silicon carbide powder

27. • Total sample of MR fluid prepared = 500 cm³
• CIP by volume = 100 cm³ = 100 7.8gm/cm³ = 780 gm
• SiC by volume=100 cm³ = 100 3.22 gm/cm³ = 322 gm
• volume of base fluid = 300 cm³ = 300 0.638 gm/cm³
= 191.4 gm
• These three components of MR fluid in above mentioned
proportion was mixed and stirred in funnel. Thus required MR
fluid has been prepared for conducting experiment.

28. Parameters used for experimentation
Parameter Conditions
Rotational speed of tool core 500 rpm
Current 4A
Working gap 0.66mm
Workpiece material Ferromagnetic
SiC abrasive mesh number 800
Speed of stepper motor 1 rps

29. Experimental setup with integrated 4th axis

30. Motion control with the help of
software
• Two software have been used:
– ACR View 1505
– Pro E wildfire 4
For a particular motion, programming is done to
generate the path of the tool.
To generate the path, either code generated in pro E
can be used or code can be written manually in
ACR View.

31. ACR1505 code used to control the
motion of tool:
Flat surface 30º inclined surface 45º inclined surface
PROGRAM PROGRAM PROGRAM
RES X Y Z A RES X Y Z A RES X Y Z A
VEL 1 VEL 1 VEL 1
MOV Y/20 MOVA/-20 MOVA/-10
MOV X/2 MOV Y/20 MOV Y/20
MOV Y/-20 MOV z/1 x/-1.732 MOV z/1.414 x/-1.414
MOV X/2 MOV Y/-20 MOV Y/-20
MOV Y/20 MOV z/1 x/-1.732 MOV z/1.414 x/-1.414
MOV X/2 MOV Y/20 MOV Y/20
MOV Y/-20 MOV z/1 x/-1.732 MOV z/1.414 x/-1.414
MOV X/2 MOV Y/-20 MOV Y/-20
MOV Y/20 MOV z/1 x/-1.732 MOV z/1.414 x/-1.414
MOV x/2 MOV Y/20 MOV Y/20
MOV Y/-20 MOV z/1.414 x/-1.414

32. Important terminology used in ACR
View programming:
• RES X Y Z A
• VEL
• MOV
• ENDP
For step over along inclined plane, the two axis
changes its coordinate accordingly

33. Manual programming
b
a
z h
Z= h sinα
x X =h cosα

34. Result and conclusion
• Perpendicular angle between tool tip and
work surface can be achieved for any surface
after integration of 4th axis

35. Setup for finishing flat surface Tool tilting for 30° surface
Tool tilting for 45° surface Tool tilting for curve surface

36. Surface roughness with 3 axis setup [1]
No. of finishing Ra (nm) of flat Ra (nm) of 30º Ra (nm) of 45º Ra (nm) of
passes surface surface surface curve surface
0 1334.1 1452.3 2739.3 1754.7
15 812.3 1296.1 1949.4 1513.2
%ΔRa -39.13 -10.74 -28.84 -13.74
Surface roughness with 4 axis setup
No. of finishing Ra (nm) of flat Ra (nm) of 30º Ra (nm) of 45º Ra (nm) of
passes surface surface surface curve surface
0 145.4 120.7 142.6 164.8
15 69.3 61.4 76.7 97.7
%ΔRa - 52.33 -49.13 - 46.21 -40.71

37. Comparison of improvement in surface finish after 15 passes

38. Conclusion
• With 3 axis setup, improvement in surface finish varies
significantly for different surfaces.
• Much improvement has been observed in the case of flat
surfaces with respect to inclined or curved surfaces.
• improvement in surface finish is almost same for flat as well
as curved or inclined surface after integration of 4th axis .
• Tool tilting provides perpendicular angle between the tool tip
and the work surface, so maximum magnetic field intensity
can be used to get better surface finish

39. Scope for future work
• Surface like sphere can not be finished by existing setup. 5th
and 6th axis can be integrated to finish more complex
geometry.
• Requirement of a mechanism to reduce the temperature of the
coil while applying high current so that continuous finishing
can be done for longer period of time

40. References
• [1] A.K.Singh, S.Jha, P.M. Pandey, Design and development of nanofinishing
process for 3D surfaces using ball end MR finishing tool, International Journal of
Machine Tools and Manufacture 51 (2011) 142-151.
• [2] S. Jha, V.K. Jain, Design and development of magnetorheological abrasive flow
finishing (MRAFF) process, International Journal of Machine Tools and
Manufacture 44/10 (2004) 1019-1029
• [3] Bongsu Jung, kyung-In-Jang, Byung-Kwon Min, Sang Jo Lee, Jongwon Seok
, Magnetorheological finishing process for hard materials using sintered iron-CNT
compound abrasives, International Journal of Machine Tools and Manufacture, 49
(2009) 407-418.
• [4] A.Sidpara, V.K. Jain, Experimental investigations into forces during
magnetorheological fluid based finishing process, International Journal of
Machine Tools And Manufacture 51 (2011) 358-362.
• [5] S.Jha ,V. K. Jain, Modeling and simulation of surface roughness in
Magnetorheological abrasive flow finishing (MRAFF) process, Wear 261(2006)
856-866.

41. Thank you