Optimization of process parameters of wear and ...

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198

Optimization of process parameters of wear and hardness characterization of industrial ceramic coatings using Taguchi design approach

involve the requirements of one or more of the properties like wear resistance, corrosion resistance, erosion resistance, thermal resistance, fatigue strength, creep strength and pitting resistance. Among the various surface modification methods, the thermal spray processes are widely recognized. Two-wire electric arc and atmospheric plasma spraying process are most commonly used in industries. The typical applications [18] of Ceramic Coatings are 1. General manufacturing industry:- Extrusion dies, threaded guides, forging tools, wire drawing Capstans, cam followers, roller bearings, hot forming dies. 2. Gas turbine industry:- Turbine Nozzles , Jet engine, Jet engine manifold rings, Gas turbines fan seals, Aircraft flap tracks, expansion joints, fan blades. 3. Petroleum Industry: - Pump plungers, compressor rods. 4. Chemical Process Industry: - Gate Valve, pump components. 5. Paper / Pulp Industry: - Printing rolls, liquor tanks. 6. Automotive Industry: - Piston rings, cylinder liners.

ES

Abstract—The state of the art methods used to manufacture the coating materials in atmospheric plasma spray process and the level of process control employed in today’s coating equipment provides an excellent coating over a broad range of application requirements. The various characteristics of coatings depend on coating material, spray parameters, spray equipment and component configurations. Amongst the many characteristics, the controlled porosity, optimized hardness which is the demanding requirements of wear-resistant application, specific coating thickness and resistance to wear plays an important role in deciding the quality of coating material.

Dr.J.Fazlur Rahman

Professor Emeritus, Mechanical Engineering Department H.K.B.K. College of Engineering Bangalore, India [email protected]

T

Mohammed Yunus

Assistant Professor, Mechanical Engineering Department H.K.B.K. College of Engineering Bangalore, India [email protected]

The present study deals with two parts. In the first part, wear tests were conducted on three types of industrial coatings, namely, Alumina, Alumina-Titania (AT) and Partially Stabilized Zirconia (PSZ) under three control parameters at different levels. In the second part, Rockwell hardness tests were conducted on other four advanced ceramic coatings, namely, Super- Z alloy, Zirconia Toughened Alumina, AT, PSZ under four parameters at different levels.

IJ A

Using the above experimental data, Taguchi technique has been employed in optimization of various parameters, which controls the wear, like applied pressure, sliding distance, sliding velocity and type of coatings with their significance in respect of wear. Similarly, the influence of plasma spray torch power, standoff distance, type and thickness of coatings on the hardness have been assessed using orthogonal array, S/N ratio and ANOVA with their confirmation tests. Optimal combination of parameters is found out. A good agreement has been found between the estimated and experimental results within the preferred significant level. Keywords- Ceramic coatings; Wear; Hardness; Taguchi Design Approach; ANOVA; S/N ratio; Plasma; PSZ; Super-Z alloy; Confirmation test.

I.

INTRODUCTION

Thermal Sprayed Surface Coatings are used extensively for a wide range of industrial applications [1-2]. The selection of a technology to engineer the surface is an integral part of the component design. Accordingly, the first step in selecting surface modification techniques is to determine the surface and the substrate engineering functional requirements [20]. These

ISSN: 2230-7818

A. Taguchi method Taguchi method is important tool for the robust design in obtaining the process and product conditions which are least sensitive to noise to produce high quality products with low manufacturing costs [11]. It involves various steps of planning, conducting and evaluating the results of specially designed tables called “orthogonal array” experiments to study entire parameter space with minimum number of trials to determine the optimum levels of control parameters [12]. A quality loss function is then designed to evaluate the deviation between experimental value and desired value. Taguchi method combine experiment design theory and quality loss function. Taguchi method recommends the use of loss function which is then transformed into a S/N ratio to measure the performance characteristic deviating from the desired value and then S/N ratio for each level of process parameters is evaluated based on average S/N ratio response analysis and greater S/N ratio is corresponding to better quality characteristic irrespective of category and quality is evaluated based on average S/N ratio response analysis and greater S/N ratio is corresponding to better performance characteristic regardless of category and quality. To find which process parameters are statistically

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Page 193

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198

significant, Analysis of Variance (ANOVA) to be performed [310]. Finally, to verify the optimal process parameters obtained from the parameter design, confirmation test to be conducted. To find the optimal combinations the following step by step procedure is followed for the DOE[11-12]. Fig.1. Taguchi’s methodology

B. Hardness test The Rockwell hardness number was determined by pressing a hardened steel ball indenter or diamond cone penetrator against a test specimen and resulting indentation depth was measured as a gauge of the specimen hardness using C-scale.

II.

EXPERIMENTAL PROCEDURE:

Table1. Process parameters and levels of the experimental design Level 1

Level 2

Level 3

Applied Pressure(MPa)

Parameters

Labels A

0.1

0.2

0.3

Sliding Distance ( m) Sliding velocity (m/sec) Type of Coating

B C D

4 2.5 PSZ

6 7.5 AT

8 12.5 Alumina

IJ A

ES

Five different commercially available ceramic coatings powders namely, Alumina (Al2O3), Alumina-Titania (Al2O3TiO2), Partially Stabilized Zirconia (PSZ), Zirconia toughened alumina (ZTA consist of 80% alumina and 20% PSZ) and Super-Z alloy (20% alumina and 80% PSZ) were used for the preparation of coatings[1-2]. A 40 KW Sulzer, Metco plasma spray system with 7MB gun is used for this plasma spraying of coatings[1]. Mild steel plates of 50x50x6 mm and cylindrical pins of 6 mm diameter and 21mm length were used as substrate to spray the ceramic oxides. They were grit blasted, degreased and spray coated with a 50 to 100 microns Ni Cr Al bond coat. The ceramic TBC were then plasma sprayed using optimum spray parameters. In this study, two response parameters such as wear and hardness tests were considered.

T

C. Taguchi Experimental Design for wear test In wear characterization of ceramic coatings, the design of experiment using the results of weight loss were carried out with four process parameters [13-15] each at three levels and the feasible space to assess quality of output and values for the four parameters of wear study were defined by varying the applied pressure, sliding velocity, sliding distance and type of coating for a range are tabulated in table1. The fractional factorial design layout reduces to L27 type [15] and it requires twenty seven trials are shown in table2. The interaction between A and C process parameters were taken to evaluate the effect of PV (product of applied pressure and sliding velocity) factor[1].

A. Wear test The pin-on-disc testing machine was used to measure the wear of material weight loss by conducting dry sliding wear tests [16-21]. This instrument consists of a pin is mounted on a stiff lever, designed as a frictionless force transducer and pressed against a rotating disk. Generally pin surface is coated with ceramic oxide to different thicknesses using plasma spray process, fixed to an arm and pressed with a known force. The measurement includes RPM, Wear and Frictional force to measure effect of sliding speed, applied pressure, and weight loss on the wear characteristics of different types of coatings. As the disc is rotated, resulting frictional forces acting between the pin and the disc are measured by using a strain gage sensor.

Table 2. L27 Orthogonal Array used in Taguchi method

Trials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

A 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3

B 1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3 1 1 1 2 2 2 3 3 3

C 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

AXC 1 2 3 1 2 3 1 2 3 2 3 1 2 3 1 2 3 1 3 1 2 3 1 2 3 1 2

D 1 2 3 2 3 1 3 1 2 2 3 1 3 1 2 1 2 3 3 1 2 1 2 3 2 3 1

Table 3. Experimental layout and results of summary for Wear test

ISSN: 2230-7818

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Page 194

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198 B

C

D

Weight loss in mg

S/N ratio in dB

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

4 4 4 6 6 6 8 8 8 4 4 4 6 6 6 8 8 8 4 4 4 6 6 6 8 8 8

2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5 2.5 7.5 12.5

PSZ AT A AT A PSZ A PSZ AT AT A PSZ A PSZ AT PSZ AT A A PSZ AT PSZ AT A AT A PSZ

3.0 1.8 5.25 3.8 4.75 8 5.6 8 8 3.5 3.6 14 10 10 20 8 11 25 6.5 12 16 9 16 25 12 16 24

9.54 5.11 14.40 11.59 13.53 18.06 14.96 18.06 18.06 10.88 11.13 22.9 20 20 26.02 18.06 20.83 27.96 16.25 21.58 24.08 19.08 24.08 27.96 21.58 24.08 27.6

Δ = 9.22 dB

B. Analysis of Variance (ANOVA) ANOVA is used to determine the most significant factor [315] affecting the optimum combination of process parameters on output quality and characteristic using the quantities such as degree of freedom (f), sum of squares (SS), variance (V), percent contribution of each factor (F-ratio) and then contribution ratio or contribution of variance were determined. From the table 5, it is observed that highest contribution ratio is for type of coating (B) while Temperature on coating side (A) is the lowest and thickness of Coating (C) has moderate value between the other two. Tables 5 illustrate the average S/N ratio values for weight loss. Tables 6 show the results of ANOVA. It is observed that the Applied Pressure (42.13%) is most significantly influences the material or weight loss followed by sliding velocity (27.16%), sliding distance (20.36%) and type of coating (0.9714%) and (3.52%) reveals that the interaction effect of the process parameters is also acceptable. Table 3. Mean S/N Ratio Response Table for Wear test Symb ol A B

C

III.

RESULTS AND DISCUSSION OF WEAR TEST

D

AXC

IJ A

A. Results of wear test There are twenty seven different tests were conducted using the control factor combinations in the specified orthogonal array table value. Nine specimens were prepared for each set of parameters to prepare complete response table. Taguchi method uses the S/N (signal-to-noise) ratio. S/N ratio is used to determine the most significant factor. There are three types of S/N ratio criteria for optimization; smaller the best, larger the better and nominal the best [5-12]. To get the better performance of results, smaller the weight loss is desired and hence smaller the best criteria has been selected and following expression was used for analysis. Where y represents the observed data and n number of tests in one trial [15]. The mean responses of S/N ratio for weight loss are calculated for all factors and are tabulated. A sample calculation for one of factor (A) is shown below. 9.54+5.11+14.4+11.59 +13.53+18.06+14.96+18.06+18.06 Level1=------------------------------------------------------------------------ =13.7 dB 9 10.88+11.13+22.9+20+20+26.02+18.06+20.83+27.96 Level2= -------------------------------------------------------------------- = 19.75 dB 9 16.25+21.58+24.08+19.08+24.08+27.96+21.58+24.08+27.6 Level3=------------------------------------------------------------------------=22.92dB 9 Difference, Δ (max-min) = 22.92-13.7

ISSN: 2230-7818

T

A

Factors

Pressure

Level1 -13.7

ES

Experiment trials (Recipes) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Sliding Distance Sliding Velocity Type of coating Interaction effect(PV factor)

-15.09 -15.77 -19.43

Level2

Level3

Δ

Rank

-19.75

-22.92

9.22

1

-20.035

-21.24

6.15

3

-17.6

-23.004

7.234

2

-18.025

-18.92

1.405

5

18.392

17.682

2.62

4

20.3011

Table 4. The optimal set of factors for wear test

Symbols A. B. C. D.

Parameters Pressure Sliding Distance Sliding Velocity Type of coating

Optimum setting 0.3 MPa 8 Km 25 m/sec PSZ

Table 5. Analysis of Variance (ANOVA) results for Wear test Factors A B C D AXC Pooled error Total

Sum of squares 395.018 190.897 254.622 9.10801 33.02

Degree of freedom 2 2 2

54.968 937.634

2 4 14

variance

F-ratio

197.509 95.4493 127.310 9 4.554 8.255 3.923

50.35 24.331 32.452 1.161 2.104 1

% Contribution ratio 42.13 20.36 27.16 0.9714 03.52 05.862

26

100

Figure 2. Average Response S/N ratio Graph for Wear test

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Page 195

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198

IV.

RESULTS AND DISCUSSION OF HARDNESS TEST

A. Design of Experiment for hardness test Table 7 shows design of experiment for hardness characterization of ceramic coatings with four process parameters each at four levels. B. Results of hardness test For the above test, sixteen different hardness tests were conducted using the process parameters combinations in the specified orthogonal array L16 as shown in table 8 [3]. To get the better performance, larger the hardness number is desired and in this case, the larger the best criteria has been selected for S/N ratio in the analysis.

Confirmation test Furthermore, the confirmation test is conducted to verify the improvement of results and to predict the optimum performance at the selected levels (since all factors have a confident level more than 90%) of significant parameters such as A3, C3, B3 and D1. The most optimal set of combination of parameter is found out. The predicted mean (M) of the response characteristic of TBC can be expressed as[6-7], [9-10] M = (A3-T) + (B3-T) + (C3-T) + (D1-T) + T, where T= current grand average of S/N ratio Μ = (22.92-18.792) + (21.24-18.792) + (23.004-18.792) + (19.43-18.792) + 18.792=30.22dB A confidence interval (C.I) has to be evaluated on the for the M using the following expression [9-10] =4.9

Parameters

Label

Level 1

Level 2

Level 3

Torch power (KW)

A

16

25

30

Type of Coating

B

SuperZ

ZTA

PSZ

C

100

110

120

D

100

150

200

Standoff distance (mm) Coating thickness ( micron)

IJ A

ES

C.

Table7. Process Parameters and levels of the experimental design

T

Additionally, it is seen that most significant factors can be determined by the larger difference of S/N ratio [15]from figure2 and table 5 gives the results of ANOVA, it is found that mostly significant factor with contribution ratio, that decreases the weight loss is Applied pressure followed by the Sliding velocity, sliding distance and the type of coating.

Where Nf=

and R= number of trials to run confirmation test. Using ANOVA table ve= 3.923, fe=14 and Fα (1, 14) =4.6 at 95% confidence level and tabulated. At the 95% confidence level, the predicted mean of the weight loss (WL) was found to be in the range of 25.32 dB < WL > 35.12 dB. Table 6. The comparison between actual and predicted results of Wear test

Level Wear in mg S/N Ratio in dB

Estimation A3B3C3D1 25.7 30.22

ISSN: 2230-7818

Optimum Level Experimental A3B3C3D1 24 27.6

Difference 1.7 0.6

Level 4 40 AT 140 300

Table 8. Experimental layout and summary of results for Hardness test S.No.

A

B

C

D

1 2 3 4 5

16 16 16 16

Super-Z ZTA PSZ AT Super-Z

100 110 120 140 110

ZTA PSZ AT Super-Z ZTA PSZ AT Super-Z ZTA PSZ AT

100 140 120 120 140 100 110 140 120 110 100

6 7 8 9 10 11 12 13 14 15 16

25 25 25 25 30 30 30 30 40 40 40 40

S/N ratio in dB

100 150 200 300 200

Rockwell hardness Number 110 109 90 115 116

300 100 150 300 200 150 100 150 100 300 200

118 85 120 120 112 83 106 125 115 86 120

41.43 38.59 41.58 41.58 40.98 38.38 40.51 41.94 41.21 38.69 41.58

40.83 40.75 39.08 41.21 41.29

Table 9. Mean Response S/N ratio of the hardness test

Torch power(KW), A

40.47

40.72

40.37

40.86

0.49

R a n k 3

Type of Coating, Standoff distance (mm), Coating thickness ( micron),

B

41.41

41.09

38.69

41.22

2.72

1

C

40.56

40.31

40.86

40.68

0.55

2

D

40.29

40.66

40.73

40.73

0.44

4

Parameter and their Labels

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Levels I

II

III

IV

Page 196

Δ

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198

Table 10. ANOVA Results of hardness test Parameters

SS

DOF

Variance

Fratio

Contribution ratio (%)

0.20531

6.56

2.84

A

0.61592

3

B

19.8011

3

6.6

211

91.23

C

0.64567

3

0.21522

6.88

2.975

0.54772

3

0.18257

5.83

2.524

0.094

3

0.0313

D Pooled error

Total

21.704

Most significant factor is Super-Z alloy (B1) followed by stndoff distance 120mm, Power of 40KW and least significant factor is when the thickness of coating is 200micron. From ANOVA (table 10) results, it is inferred that maximum contribution ratio is for coating (91.23%) followed by stndoff distance (2.975%), Power (2.84%) and least significant factor is the thickness of coating (2.524%). V.

The following observations were confirmed based on the experimental and Taguchi analysis results, which helps for better performance of ceramic coatings. 1.

15

C. Confirmation test The predicted mean (M) of the optimal set of results and confidence interval (C.I.) were obtained by using the following equations, Μ = (40.855-40.602)+(41.41-40.602) + (40.86-40.602) + (40.733-40.602) +40.602 = 42.052dB

2.

The predicted mean of the response S/N ratio for the hardness (HRC) lies in the range of 41.294dB < HRC > 42.81dB at the confidence level of 95% (=0.05). actual

and

4.

estimated

5.

Optimum Level

Estimation

Experimental

A4B1C3 D4 116

A4B1C3 D4 122

Difference

parameters

IJ A

Level Rockwell hardness number S/N Ratio in dB

between

42.052

In respect of wear characterization using average response of S/N ratio it is inferred that, the optimum set of parameters are A3, B3, C3 and D1 at optimum conditions of Applied pressure (0.3MPa), sliding distance (8 Km), sliding velocity (12.5 m/sec) and type of coating (PSZ). With the above set parameters, the optimal weight loss is 25.7 mg. The type of coating i.e. PSZ alloy shows the least significant control parameter, while the applied pressure is the most significant control parameter in case of wear analysis. In respect of hardness assessment, type of coating i.e. super-Z alloy, exhibits most significant control parameter for achieving high hardness while the thickness of coating shows least significant parameter. From the ANOVA, contribution ratio for wear and hardness tests are tabulated below.

ES

3.

=0.76

Table10. Comparison of results performance of hardness test

41.72

06

A B C

2.15

Figure 3. Average Response S/N ratio Graph for Hardness test

Contribution Ratio (%) for wear test 42.13(highest) 20.36 27.16

D

Contribution Ratio (%) for hardness test 2.84 91.23(highest) 2.975

0.9714(lowest)

2.524(lowest)

6. It is noticed that, there was a good agreement between estimated and actual values obtained in respect of wear and hardness within the preferred significant level. 7. Among the three coatings, Alumina, AT and PSZ, PSZ showed maximum wear resistance, whereas super – Z alloy exhibits better when compared to ZTA, PSZ and AT. VI. [1]

ISSN: 2230-7818

CONCLUSIONS

T

Tables 10 show the results of ANOVA. It is observed that the type of coating (91.23%) is most significantly influences the hardness followed by standoff distance (2.975%), torch power (2.84%) and thickness of coating (2.524%). Also it is seen from fig.3 the most significant factor is type of coating i.e. Super-Z alloy.

REFERENCES.

Dr.J.Fazlur Rahman and Mohammed Yunus,“Benefits of TBC Coatings on Engine applications”, International conference, INCAM 2009 at Kalsalingam University, Tamil Nadu, India, March 2009.

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Page 197

Mohammed Yunus* et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 9, Issue No. 2, 193 - 198

[4]

[5]

[6]

[7] [8]

IJ A

[9]

[10] Hari singh, Pradeep Kumar, “ Tool wear optimization in turning operation by Taguchi method”, Indin Journal of Engineering and Material Sciences, volume11, February 2004, pp. 19-24. [11] Roy R.K.,“Design of Experiments using The Taguchi Approach: 16 Steps to Product and Process Improvement”. 2001,John Wiley & Sons, inc. [12] Roy R.K., “A primer on the Taguchi method”. Competitive manufacturing series, 1990, Van Nistrand Reinhold, Newyork. [13] Atik E, Yunker U, Meric C , “The effects of conventional heat treatment and boronizing on abrasive wear and corrosion of SAE1010, SAE 1040, D2 and 304 steels”, Tribol Int., Vol.36, 2003, pp.155–161. [14] S.S. Mahapatra and Vedansh Chaturvedi “Modelling and analysis of abrasive wear performance of composites Using Taguchi approach” Int. J. Engineering, Science and Technology, Vol. 1, No. 1, 2009, pp. 123135. [15] Ferit Ficici, Murat Kapsiz and Mesut Durat, “Applications of taguchi design method to study wear behaviour of boronized AISI 1040 steel”, Int. J. Physical Sciences Vol. 6(2), 18 January, 2011, pp. 237-243. [16] Buckley, D.H. and Kazuhisa Miyoshi, “Friction and wear of ceramics”, J.of wear, Vol. 100, 1984, pp. 333-353. [17] Gane, N. and Beardsley, R., “Measurement of wear of engineering materials using pin on disc machine”, Proc. Industrial Tribology Conference, Melbourne, 1987, pp. 187. [18] Hannink, R.H.J., Murray, M.J. and Scott, H.G., “Friction and wear of Partially Stabilized Zirconia: basic science and practical applications”, J. of wear, Vol. 100, 1984, pp. 355-366. [19] Ishigaki, J., Nagata, R. and Iwasa, M., “Friction and wear of Partially Stabilized Zirconia”, I. Mech. E., 1987, pp. 609-614. [20] Pfender, E., “Fundamental studies associated with plasma spray process”, J. of surface coating technology, Vol. 34, No.1, 1988, pp. 1-14. [21] Steffans, H.D., “Coatings for High Temperature Applications”, Applied Sci., NewYork edition, Lang E., 1983, pp. 121.

T

[3]

Dr.J.Fazlur Rahman and Mohammed Yunus, “Mechanical and Tribological characteristics of Tungsten Carbide Cobalt HVOF coatings” International conference held at Anjuman college of Engineering, Bhatkal October 2008. S.kamaruddin, Zahid A. Khan and S.H.Foong, “Application of Taguchi Method in the Optimization of injection Moulding Parameters for Manufacturing Products from Plastic Blend”, 2010, IACSIT international J. Engineering and Technology, volume 2, number 6, December 2010, ISSN: 1793-8236, PP. 574 – 580. Barriere, Th., Liub, B., and Gelin, J.C., “Determination of the optimal process parameters in metal injection molding from experiment and numerical modelling”, 2003, J. Material Processing Technology, 143144, PP. 636 – 644. Ferit Ficici, Murat kapsiz and Mesut Durat, “Applications of Taguchi design method, in the Optimization of injection Moulding Parameters for Manufacturing Products from Plastic Blend”, 2010, IACSIT international J. Engineering and Technology, volume 6, number2, January 2011, PP. 237 – 243. Noordin M. Y., Venkatesh V. C., Sharif.S., Elting. S., Abdullah. A. Application of response surface methodology in describing the performance of coated carbide tools when turning AISI 1045 steel. Journal of Materials Processing Technology 145, 46 (2004). Lin T. R. et al., “Optimization technique for face milling stainless steel with multiple performance characteristics” Int. J Adv Manufacturing Technology 19, 330 (2002). L.A. Dobrzañski, J. Domagala, “Application of Taguchi method in the optimization of filament winding of thermoplastic composites” J.F. Silva International Scientific Journal published monthly as the organ of the Committee of Materials Science of the Polish Academy of Sciences, Volume 28, Issue 3March 2007, Pages 133-140. P. Sharma, A. Verma, R.K. Sidhu, O.P. Pandey, Process parameter selection for strontium ferrite sintered magnets using Taguchi L9 orthogonal design, Journal of Materials Processing Technology 168 (2005) 147-151.

ES

[2]

ISSN: 2230-7818

@ 2011 http://www.ijaest.iserp.org. All rights Reserved.

Page 198