Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle Using Taguchi Design Method

IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 10, 2015 | ISSN (online): 2321-0613

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method B. Suresh Babu1 Dr. P. Suresh Babu2 Associate Professor 2Principal & Professor 1,2 Department of Mechanical Engineering 1 Sri Vasavi Institute of Engineering and Technology, Nandhamur, Krishna Dist -52163 A.P 2Challapathi Institute of Engineering and Technology Guntur, Andhra Pradesh India 1

Abstract— Here, we study about, influence of various machining parameters like current, grit size %iron, and speed.

In the present study, experiments are conducted on En8 steel material with four factors and five levels by using abrasive magnetic particle and try to find out optimum surface roughness. By using taguchi method. Of orthogonal array conventional number of experiments is reduced to nine by choosing four factors and three level of experiments and proved the result is same. This paper attemptsto introduce how Taguchi parameter design could be used in identifying the significant processing parameters and optimizing the surface roughness abrasive magnetic particle of operations.

In this study, it was observed that, the order of significance of the main variables is as A3 > B1 > C1 > D3 Key words: current (A), grit size (B), %iron(C), speed (D),. abrasive magnetic particle, Taguchi parameter design I. INTRODUCTION Extrude Hone Corporation, USA, originally developed the AFM process in 1966. Since then, a few empirical studies [1– 5] have been carried out and also research work regarding process mechanisms, modeling of surface generation and process monitoring of AFM was conducted by Williams and Rajurkar [6] during the late 1980s. Their work [7] was mainly related to online monitoring of AFM with acoustic emission and stochastic modeling of the process.

Shinmura et al [8] have studied basic principle of the MAF process and concluded that the stock removal and surface finish value (Ra) increase as the magnetic abrasive particle diameter “D” increases. Ra value of the final surface finish increases as the abrasive grain diameter “d” increases.

In order to achieve smooth surface and remove surface damage, the ferromagnetic particle diameter must be chosen as a compromise of material removal rate and resulting surface finish. Small diameter abrasive grains produce good surface finish.

Kremen et al. [9,10] have proposed a model for material removal in MAF. Kim et al. [11,12] have also modeled and simulated the MAF process and concluded that the magnetic flux density in the air-gap is affected greatly by the length of the air-gap; magnetic flux density increases as the air-gap length decreases. They have also found that simulation results for surface finish agree better with the experimental data for the low magnetic flux density than they do for high magnetic flux density.

II. MAGNETIC ABRASIVE FINISHING Magnetic abrasive finishing (MAF) process is the one in which material is removed in such a way that surface

finishing and debarring are performed simultaneously with the applied magnetic field in the finishing zone.

The technology for super finishing needs ultra clean machining of advanced engineering materials such as silicon nitride, silicon carbide, and aluminum oxide which are used in high- technology industries and are difficult to finish by conventional grinding and polishing techniques with high accuracy, and minimal surface defects, such as micro cracks. Therefore, magnetic abrasive finishing (MAF) process has been recently developed for efficient and precision finishing of internal and flat surfaces. This process can produce surface finish of the order of few nanometers.

A. Formation of Magnetic Abrasive Brush: A forming mechanism of a magnetic abrasive brush can be clarified from observations made on in various abrasive volumes; mass of abrasive was varied from 0.1 to 1.0 g by 0.1 g. Fig.1.10shows typical cases of 0.1, 0.2 and 0.6 g. The characteristics of the observed brush are as follows: – At an abrasive small volume, the diameter of each bundle is in the order of a few hundred micrometer that are separated from each other.

– With an increase of volume, the bundles get closer to other and the diameter of the bundles increase to several hundred micrometer, corresponding to several abrades.

– At large abrasive volume, the maximum diameter of a bundle does not increase but the number of bundles of several diameter increase III. EXPERIMENTAL SET UP[13].

A. Requirements of Set Up Fundamental requirements of the experimental set-up are: 1) 2) 3) 4)

Magnetization Unit Electromagnet Motion Control Unit.

Work Piece Fixture.

1) Magnetization Unit Basic purpose of magnetization unit is to generate the required magnetic field to assist the finishing process. Main parts of magnetization unit are – – –

D.C. Power supply Electromagnet

2) Electromagnet To energize the electromagnet a constant voltage/current D.C. regulated power supply of output voltage 220 V and output current from 0 to 1A was used. By controlling the induced current from D.C. power supply the generated magnetic field can be controlled. In order to get the required current and voltage RPS(Regulated Power Supply) is used.

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395

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

By using the RPS we can get a voltage of 220V and we can vary the current between 0-2A. By using the electromagnet we can vary the intensity of the magnetic field. The electromagnet mainly consists of a iron core at the center and copper wire is wound around the core. The intensity of the magnetic field is directly proportional to the number of windings or the applied electric current. To protect the copper winding from damage varnish coating is applied around the winding. It also helps in insulating the copper wire.

3) Motion Control Unit The workpiece is firmly fixed in the chuck of the lathe machine. The speed of the workpiece is maintained with the help of the motor that is provided in the lathe machine. The experimentation is carried out at a constant speed i.e., 355rpm.

4) Fixture And Work Piece The material chosen is Mild Steel(EN-8). The work piece was made in cylindrical shape. The diameter of the work pieces are 35mm. The work piece is hold firmly in the chuck of the lathe machine.

5) Specifications of lathe machine:  Power of the Motor : 2.2 H.P  No.of Spindle Speeds : 9  Hole through Spindle : 38mm  Length of bed : 1800mm  Height of centres : 510mm  Admit between centres : 1000mm  Swing Over bed : 360mm B. Experimental Procedure The parameters that are kept constant during the experimentation are: Parameter Value Size of the iron particles 40# Finishing Time 15 min.

The variable parameters and their ranges are: Parameter Value Mesh size of the abrasive particles

18# - 60#

Current(amp)

0.1A – 0.5A

Percent composition of iron in MAP’s

60% - 90%

Abrasive Powder Used

SiC

Speed

355, 535 and 835 rpm

SPEED=355 RPM Initial Roughness value=1.685 GRI T Current(Amps )

0.1

Conversion grit sizes into measurements in inches and microns.

GRI T

MAXI MUM

MINI MUM

20

INCH ES AVE RAG E 0.037

0.053

0.026

30

0.022

0.032

46

0.014

0.022

60

0.01

0.016

0.014 0.009 5 0.006 5

SIZ E(#)

MICR ONS AVE RAG E 940

MAXI MUM

MINI MUM

1346

660

559

813

356

356

559

241

254

406

165

The following are the procedural steps during MAF process.

1) Work pieces were initially ground by cylindrical grinder to give most same initial surface roughness value.

Cylindrical grinding is done at following conditions: Speed = 1440 rpm Feed = 13.33 mm/min 2) After the grinding process, the work pieces were manually cleaned by acetone to remove the foreign particles. Initial surface roughness values were measured by using Tally surf analyzer with least count of 0.001µm 3) To conduct the surface finish experiments, the work piece was mounted on the lathe. The work piece was made parallel to the electromagnet using a dial indicator (least count-0.01mm) to maintain proper gap between them. The work piece was made parallel in both X and Y direction. The position of work piece in XY plane was kept in such a way that the center of the electromagnet coincide with the center of the work piece.

4) Working gap between electromagnet and work piece was maintained by a filler gauge and this gap was filled with the MAP. The amount of MAP depends on the working gap. Percent by weight method was used to calculate the amount of MAP in the working gap 5) The current to the electromagnet was supplied and got it energized and abrasive powder fill between the electromagnet and work piece making FMAB. By giving rotation to the magnet, this FMAB performs the actual finishing operation.

6) After completing the finishing operation, work piece was again cleaned manually using acetone and final surface roughness value was measured.

Abrasive powder=SiC 60

46

Ra-Surface Roughness 20

30

%iro n

Ra

%improvemen t

Ra

%improvemen t

Ra

%improvemen t

Ra

%improvemen t

90

1.29 2

39.3

1.3

38.5

1.32

36.5

1.33

35.5

80

1.3

38.5

37.1

1.31

37.5

1.34

34.5

70

1.31

37.5

36.5

1.33

35.5

1.35

33.5

60

1.32

36.5

34.3

1.34 8

33.7

1.35 7

32.5

1.31 4 1.32 6 1.34 2

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396

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

0.2

0.3

0.4

0.5

90

1.28

40.5

80

1.29

39.5

70

1.3

38.5

60

1.31

37.5

90

1.27

41.5

1.29 8 1.30 4 1.31 1.31 8 1.28

80

1.28

40.5

1.29

70

1.29

39.5

60

1.3

38.5

90

1.25

43.5

80

1.26

70

1.27

60

1.28

90

1.22

80 70 60

38.7

1.31

37.5

1.32

36.5

38.1

1.3

38.5

37.5

1.32

36.5

36.7

1.33

35.5

40.5

1.29

39.5

1.33 4 1.34 1.34 8 1.3

39.5

1.28

40.5

1.32

36.5

1.3

38.5

1.31

37.5

1.33

35.5

1.31

37.5

1.32

36.5

1.33

35.5

1.26

42.5

1.27

41.5

1.28

40.5

42.5

1.28

40.5

1.27

41.5

1.29

39.5

41.5

1.29

39.5

1.29

39.5

1.32

36.5

40.5

1.3

38.5

1.3

38.5

1.31

37.5

46.5

1.23

45.5

1.25

43.5

1.26

42.5

1.23

45.5

1.24

44.5

1.26

42.5

1.27

41.5

1.24 1.25

44.5 43.5

1.26 1.28

42.5 40.5

1.27 1.28

41.5 40.5

1.31 1.3

37.5 38.5

35.1 34.5 33.7 38.5

Table 1: Effect of % composition of iron powder, Grit Size and current on surface roughness of EN-8 during MAF process when speed is 355 rpm SPEED=535 RPM Initial Roughness value=1.685 Abrasive powder=SiC Ra-Surface Roughness GRIT Current(Amps)

0.1

0.2

0.3

0.4

0.5

60

46

%iron

Ra

%improvement

90

1.19

80

1.2

70

30

20

Ra

%improvement

Ra

%improvement

Ra

%improvement

49.5

1.2

48.5

1.21

47.5

1.23

45.5

48.5

1.22

46.5

1.23

45.5

1.24

44.5

1.21

47.5

1.23

45.5

1.24

44.5

1.26

42.5

60

1.23

45.5

1.24

44.5

1.26

42.5

1.27

41.5

90

1.17

51.5

1.18

50.5

1.2

48.5

1.22

46.5

80

1.18

50.5

1.21

47.5

1.22

46.5

1.23

45.5

70

1.2

48.5

1.22

46.5

1.23

45.5

1.25

43.5

60

1.22

46.5

1.23

45.5

1.25

43.5

1.26

42.5

90

1.14

54.5

1.17

51.5

1.19

49.5

1.21

47.5

80

1.15

53.5

1.19

49.5

1.21

47.5

1.22

46.5

70

1.17

51.5

1.2

48.5

1.23

45.5

1.24

44.5

60

1.2

48.5

1.22

46.5

1.24

44.5

1.25

43.5

90

1.12

56.5

1.16

52.5

1.18

50.5

1.2

48.5

80

1.13

55.5

1.18

50.5

1.2

48.5

1.21

47.5

70

1.15

53.5

1.19

49.5

1.22

46.5

1.22

46.5

60

1.17

51.5

1.21

47.5

1.23

45.5

1.24

44.5

90

1.08

60.5

1.14

54.5

1.14

54.5

1.19

49.5

80

1.09

59.5

1.15

53.5

1.17

51.5

1.2

48.5

70

1.1

58.5

1.17

51.5

1.19

49.5

1.21

47.5

60

1.14

54.5

1.19

49.5

1.2

48.5

1.23

45.5

Table 2: Effect of % composition of iron powder, Grit Size and current on surface roughness of EN-8 during MAF process when speed is 535 rpm SPEED=835RPM Initial Roughness value=1.685 Abrasive powder=SiC Ra-Surface Roughness GRIT Current(Amps)

60

46

30

20

%iron

Ra

%improvement

Ra

%improvement

Ra

%improvement

Ra

%improvement

90

1.15

53.5

1.16

52.5

1.19

49.5

1.22

46.5

80

1.17

51.5

1.18

50.5

1.21

47.5

1.24

44.5

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397

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

0.1

0.2

0.3

0.4

0.5

70

1.18

50.5

1.19

49.5

1.23

45.5

1.25

43.5

60

1.19

49.5

1.22

46.5

1.24

44.5

1.26

42.5

90

1.12

56.5

1.13

55.5

1.15

53.5

1.18

50.5

80

1.14

54.5

1.15

53.5

1.17

51.5

1.2

48.5

70

1.15

53.5

1.17

51.5

1.18

50.5

1.21

47.5

60

1.17

51.5

1.19

49.5

1.2

48.5

1.22

46.5

90

1.09

59.5

1.11

57.5

1.12

56.5

1.14

54.5

80

1.11

57.5

1.13

55.5

1.14

54.5

1.16

52.5

70

1.12

56.5

1.15

53.5

1.15

53.5

1.17

51.5

60

1.14

54.5

1.17

51.5

1.17

51.5

1.19

49.5

90

1.07

61.5

1.08

60.5

1.1

58.5

1.1

58.5

80

1.08

60.5

1.1

58.5

1.12

56.5

1.12

56.5

70

1.09

59.5

1.12

56.5

1.13

55.5

1.14

54.5

60

1.11

57.5

1.14

54.5

1.15

53.5

1.16

52.5

90

1.05

63.5

1.06

62.5

1.08

60.5

1.09

59.5

80

1.06

62.5

1.07

61.5

1.09

59.5

1.1

58.5

70

1.07

61.5

1.08

60.5

1.1

58.5

1.12

56.5

60

1.09

59.5

1.1

58.5

1.13

55.5

1.14

54.5

Table 3: Effect of % composition of iron powder, Grit Size and current on surface roughness of EN-8 during MAF process when speed is 835 rpm for users with limited knowledge of statistics, hence gained wide popularity in the engineering and scientific community.

IV. TAGUCHI’S DESIGN OF EXPERIMENTS The desired cutting parameters are determined based on An objective function with constraint is formulated to solve experience or by hand book where cutting parameters are the optimal cutting parameters using reflected. Steps of Taguchi method are as follows: Taguchi’s Design of Experiments. The optimization 1) Identification of main function, side effects and failure of process and product parameters considerably improvesthe mode. quality characteristics. A large number of experiments are 2) Identification of noise factor, testing condition and required to be conducted when the number ofparameters and quality characteristics. levels increases.

3) Identification of the main function to be optimized.

In order to reduce the number of experiments to be 4) Identification the control factor and their levels. conducted for the same number of parameters and 5) Selection of orthogonal array and matrix experiment. levels, the Taguchi’s Design of Experiment employs a 6) Conducting the matrix experiment. specially designed orthogonal array to study the 7) Analyzing the data, prediction of the optimum level and entireparameter levels with a conduct of lesser number of performance. experiments. The minimum number of experiments to 8) Performing the verification experiment and planning beconducted is calculated as, Table1 shows all Taguchi design parameters and Minimum number of experiments = [(L – 1) x P] + 1 levels. = [(3-1) × 4]+1 =9≈L9 One of the most important considerable attributes of Taguchi where, parameter design was S/N ratio. It was differ at different pL – Number of levels of fin parameters and laces P – Number of fin parameters 1 2 3 S/N RATIO LOWER THE BETER =-10LOG1/n Σn i=1 yi2 A CURRENT amp 0.1 0.3 0.5 Where, n = number of measurements Ina trial/row, B. GRIT SIZE 60 30 20 yi = the ith measured value in a run/row.

C%iron 90 70 60 By applying Taguchi’s technique one can D SPEED rpm 355 535 835 significantly reduce the time required for experimental Table 4 investigation, as it is effective in investigating the effects of multiple factors on performance as well as to study the A. Select Orthogonal Array influence of individual factors to determine which factor has Literature survey and discuss with some industrial person, we more influence and which has less (Lin, 2001). Taguchi considered four factors and three levels in ourstudy. As per method is a powerful tool for the design of high quality above parameters we select L9 orthogonal array (OA) in the systems. Taguchi method is efficient method for designing Taguchi parameter design. The layout of L9 orthogonal array process that operates consistently and optimally over a is shown in Table-2. variety of conditions. To determine the best design it requires A BG D the use of a strategically designed experiment. Taguchi s.

C%i %improve S/N curr rit spe Ra approach to design of experiments in easy to adopt and apply no ron ment ent

size

ed

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398

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

1

0.1

60

90

355

1.2 92

39.3

2

0.1

30

70

535

1.2 4

44.5

3

0.1

20

60

835

1.2 5

43.5

4

0.3

60

70

835

1.1 2

56.5

5

0.3

30

60

355

1.3 2

36.5

6

0.3

20

90

535

1.2 1

47.5

7

0.5

60

60

535

1.1

58.5

8

0.5

30

90

835

1.0 8

60.5

9

0.5

20

70

355

1.3 1

37.5

level 1 2 3 Delta Rank

2.22 52 1.86 84 1.93 82 0.98 43 2.41 14 1.65 5 0.82 57 0.66 84 2.34 54

Table 5: Analysis of raw data from table5 A current B grit C D amp size %iron Speed 1.2606 1.1706a 1.194a 1.3073 1.2166 1.2133 1.2233 1.775 1.1633a 1.2566 1.2233 1.15a 0.0973 0.086 0.0293 0.1573 2 3 4 1 Table 6:

a = optimum parameters predicted mean = A3+B1+C1+D3 – 3*y.1.1633+ 1.1706+1.194+1.15- 3*1.2135 =1.0374 Analysis of S/N ratio from table 2 A current B grit level C %iron D Speed amp size 1 -2.0106a -1.3457a -2.3273 1.5162a 2 -1.6835 -1.6494 -1.7327 -1.4504 3 -1.2805 -1.9795 -1.7412 1.1969a Delta 0.7301 0.6338 0.2285 1.1304 Rank 2 3 4 1 Table 7: a = optimum parameters predicted mean on S/N ratio = A3+B1+C1+D3 – 3*y = -1.2805-1.3457-1.5162-1.1304-3*1.6615= -0.2833 Db After raw data were collected, average effect response values (Table 3) and S/N response ratios (Table 5),respectively, were calculated based on Table 2. The calculation of average effect response values and S/Nratios were based on the following procedure. For example, the average effect for level one of Tool feed was computed using data from experimental numbers 1-3 of Table 5. The S/N ratio is calculated in thesame way. The average effects and S/N ratios for each level of cutting parameters are summarized andreferred to in the average effects response table and S/N ratios response table for surface roughness (Ra), as shown in Tables 6 and 7

Table 1: Above graphs are from raw data of

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399

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

Table 2: Above graphs are from raw data of

Table 3: Above graphs are from raw data of

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400

Experimental Analysis on Surface Roughness of Abrasive Magnetic Particle using Taguchi Design Method (IJSRD/Vol. 3/Issue 10/2015/079)

The above graphs are based on taguchi design method which proved same surface finish with minimum number of experiments.

In each graph x axis is surface roughness (Ra) series1 means current in the above graph V. CONCLUSION In the present paper, MAF setup has been designed and fabricated. The performance of the setup has also been studied. MAF process on Mild steel with the use of loosely bounded MAPs has been carried out. It is concluded maximum improvement at expt no 8 with 60.5% improvement from the results and discussion that current and circumferential speed of workpiece are the parameters which significantly influence the material removal, change in surface roughness value(∆Ra),and percent improvement in surface finish.

It also allows industry to reduce process or product variability and minimize product defects by using a relatively small number of experimental runs and costs to achieve superior-quality products. This research only demonstrates how to use Taguchi parameter design for optimizing machining performance with minimum cost. In this study, the analysis of confirmation experiments has shown that Taguchi parameter design can successfully verify the optimum cutting parameters, which are observed that, the order of significance of the main variables is as A3 > B1 > C1 > D3: current (A), grit size (B), %iron(C), speed (D),.value of surface roughness [Mean (= - 1.034 μm) and S/N ratio (-0.2833 Db.) The other two parameters %iron and grit size also effects the Ra, slightly to improved surface finish.

[3] W. Perry, Properties and capabilities of low-pressure abrasive flow media, in: SME Paper MR75-831, Society of Manufacturing Engineers, Dearborn, MI, USA, 1975.

[4] J. Stackhouse, Deburring by dynaflow, in: SME Paper MR75- 484, Society of Manufacturing Engineers, Dearborn, MI, USA, 1975.

[5] T. Kohut, Surface finishing with abrasive flow machining, in: Proceedings of Fourth International Aluminum Extrusion Technology Seminar, Washington, DC, April 1988, pp. 35–43.

[6] R.E. Williams, K.P. Rajurkar, Performance characteristics of abrasive flow machining, in: SME Paper FC89-806, Society of Manufacturing Engineers, Dearborn, MI, USA, 1989, pp. 898– 906.

[7] R.E. Williams, K.P. Rajurkar, Stochastic modelling and analysis of abrasive flow machining, Trans. ASME, J. Eng. Ind. 114 (1992) 74–81.

[8] T. Shinmura, K. Takazawa, E. Hatano, Ann. CIRP 39 (1990) 325–328.

[9] G.Z. Kremen, E.A. Elsayed, J.L. Ribeiro, Int. J. Prod. Res. 32 (1994) 1825–2817.

[10] G.Z. Kremen, E. A, V.I. Rafalorich, Int. J. Prod. Eng. 34 (1996) 2629–2638.

[11] J. Kim, M. Choi, J. Mat. Process. Technol. 53 (1995) 630– 642.

[12] J. Kim, Y. Kang, Y.H.S.W. Baeand Lee, J. Mater.

Process. Technol. 71 (1997) 384–393.

[13] B.suresh babu and DR P.suresh babu from surface Roughness Improvement of EN8 steel by Magnatic Abrasive particles 24 th addition ijifr vol 2 aug 15 2015 [14] Data of experiment is obtained from Gudlavalleru engineering college from B tech project by T . naveena jyothi

REFERENCES [1] Traditional Machining Conference, Cincinnati, OH, December, 1985, pp. 111–120.

[2] L.J. L.J. Rhoades, Abrasive flow machining and its use, in: Proceedings of Non Rhoades, Automation of nontraditional processes, in: SME Technical Paper MR 85-475, Society of Manufacturing Engineers, Dearborn, MI, USA, 1985, pp. 1–18.

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