**Table 12.**

**4.7 Confirmatory test for bead width**

*Orthogonal Array L25 (Minitab18).*

where,

**174**

**Table 11.**

η – predicted value *nm* - is the total mean

After evaluating the optimal parameter settings, the next step is to predict and verify the quality performance characteristics using the optimal parametric combination. The predicted value of the bead width is estimated by using the Eq. (2). Five experiments are conducted at the optimum parameter. The result of predicted value and experimental value of bead width is shown in **Table 19**, and it represents that

*i*¼0

*nim* � *nm* (2)

predicted value and experimental value are close to each other [9].

**Experiment no. Process parameter**

*Quality Control - Intelligent Manufacturing, Robust Design and Charts*

**P B FT**

<sup>η</sup> <sup>¼</sup> *nm* <sup>þ</sup>X<sup>0</sup>

*Orthogonal array actual value.*


**Table 13.** *S/N ratio.*


**Exp. no. Process Parameter 1**

*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter*

*DOI: http://dx.doi.org/10.5772/intechopen.93974*

**Table 15.**

**Table 16.**

**177**

*Response table for S/N ratio.*

*S/N Ratio from MINITAB 18.*

**Level Peak**

**current (P)**

**Base current (B)**

 8.115 8.661 9.411 8.483 8.495 9.013 8.652 9.528 8.562 8.736 8.417 8.609 9.559 8.881 9.580 8.653 9.835 9.274 8.504 9.293 Delta 1.720 0.613 1.163 1.045 Rank 1 4 2 3

**Pulse frequency (F)**

**Pulse on time (%)**

**P B F T BW**

21 2.425 2.445 2.415 2.43 2.451 2.43 22 3.645 3.665 3.635 3.65 3.671 3.65 23 3.13 3.15 3.12 3.135 3.156 3.14 24 2.65 2.67 2.64 2.655 2.676 2.66 25 3.87 3.89 3.86 3.875 3.896 3.88

#### **Table 14.**

*Experiment value bead width.*

*nim*- is the mean value ratio at the optimal level Average bead width = 2.83 mm *nbead width* = 2.83 + (3.152 – 2.83) + (2.950 – 2.83) + (3.068 – 2.83) + (3.027 – 2.83) = 2.83 + 0.322 + 0.238 + 0.12 + 0.197 = 3.707 mm Average S/N ratio = 8.91 *naverage S=<sup>N</sup>* = 8.91 + (9.835 – 8.91) + (9.274 – 8.91) + (9.580 – 8.91) + (9.528 – 8.91) = 8.91 + 0.925 + 0.364 + 0.67 + 0.6 = 11.5 mm % Error = *Experimental valuePredicted Value Predicted Value* \* 100 % Error = <sup>3</sup>*:*<sup>744</sup><sup>3</sup>*:*<sup>6707</sup> <sup>3</sup>*:*<sup>6707</sup> \* 100 = 1.99 %

#### **4.8 Regression equation for all the response**

The regression equation has been developed by using Minitab18 statistical software. The second-order polynomial regression equation representing the bead


*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter DOI: http://dx.doi.org/10.5772/intechopen.93974*

#### **Table 15.** *S/N Ratio from MINITAB 18.*


#### **Table 16.** *Response table for S/N ratio.*

*nim*- is the mean value ratio at the optimal level

= 2.83 + 0.322 + 0.238 + 0.12 + 0.197 = 3.707 mm

= 8.91 + 0.925 + 0.364 + 0.67 + 0.6 = 11.5 mm

<sup>3</sup>*:*<sup>6707</sup> \* 100 = 1.99 %

*Predicted Value* \* 100

% Error = *Experimental valuePredicted Value*

**4.8 Regression equation for all the response**

*nbead width* = 2.83 + (3.152 – 2.83) + (2.950 – 2.83) + (3.068 – 2.83) + (3.027 – 2.83)

*naverage S=<sup>N</sup>* = 8.91 + (9.835 – 8.91) + (9.274 – 8.91) + (9.580 – 8.91) + (9.528 – 8.91)

The regression equation has been developed by using Minitab18 statistical soft-

ware. The second-order polynomial regression equation representing the bead

Average bead width = 2.83 mm

Average S/N ratio = 8.91

*Experiment value bead width.*

**Table 14.**

**176**

**Sr. No. BW 1 (mm) trial 1**

**BW 2 (mm) trial 2**

*Quality Control - Intelligent Manufacturing, Robust Design and Charts*

**BW 3 (mm) trial 3**

1 2.78 2.8 2.77 2.785 2.806 2.79 2 2.405 2.425 2.395 2.41 2.431 2.41 3 2.13 2.15 2.12 2.135 2.156 2.14 4 2.935 2.955 2.925 2.94 2.961 2.94 5 2.515 2.535 2.505 2.52 2.541 2.52 6 2.28 2.3 2.27 2.285 2.306 2.29 7 3.095 3.115 3.085 3.1 3.121 3.10 8 2.565 2.585 2.555 2.57 2.591 2.57 9 2.325 2.345 2.315 2.33 2.351 2.33 10 3.11 3.13 3.1 3.115 3.136 3.12 11 2.615 2.635 2.605 2.62 2.641 2.62 12 2.345 2.365 2.335 2.35 2.371 2.35 13 3.345 3.365 3.335 3.35 3.371 3.35 14 2.68 2.7 2.67 2.685 2.706 2.69 15 2.475 2.495 2.465 2.48 2.501 2.48 16 3.585 3.605 3.575 3.59 3.611 3.59 17 2.775 2.795 2.765 2.78 2.801 2.78 18 2.63 2.65 2.62 2.635 2.656 2.64 19 3.375 3.395 3.365 3.38 3.401 3.38 20 2.74 2.76 2.73 2.745 2.766 2.75 21 2.425 2.445 2.415 2.43 2.451 2.43 22 3.645 3.665 3.635 3.65 3.671 3.65 23 3.13 3.15 3.12 3.135 3.156 3.14 24 2.65 2.67 2.64 2.655 2.676 2.66 25 3.87 3.89 3.86 3.875 3.896 3.88

**BW 4 (mm) trial 4**

**BW 5 (mm) trial 5**

**Average BW (mm)**

% Error = <sup>3</sup>*:*<sup>744</sup><sup>3</sup>*:*<sup>6707</sup>


**Prediction Experiment**

**Parameter/control factor Optimum parameter Level Optimum value** Peak current 1 5 180A Base current 4 5 100A Pulse frequency 2 4 125Hz Pulse on time 3 2 40%

*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter*

3.75 mm

 140 60 50 35 2.82 140 70 75 40 2.44 140 80 100 45 2.17 140 90 125 50 2.97 140 100 150 55 2.55 150 60 75 45 2.32 150 70 100 50 3.13 150 80 125 55 2.60 150 90 150 35 2.36 150 100 50 40 3.15 160 60 100 55 2.65 160 70 125 35 2.38 140 60 50 35 3.38 160 90 50 45 2.72 160 100 75 50 2.51 170 60 125 40 3.62 170 70 150 45 2.81 170 80 50 50 2.67 170 90 75 55 3.41

3.72 mm

P5B5F4T2 (180A, 100A, 125Hz, 40%) Exp.1 Exp.2 Exp.3 Exp.4 Exp.5

> 3.70 mm

Average

**Process parameter 1**

**P B F T BW**

3.78 mm 3.72 mm

Level P5B5F4T2

*DOI: http://dx.doi.org/10.5772/intechopen.93974*

*Optimum parameter for bead width.*

*Confirmatory results for bead width.*

**Table 19.**

**Exp. no.**

**179**

**Table 18.**

(180A, 100A, 125Hz, 40%)

Bead width 3.707 mm 3.744 mm S/N Ratio 11.5 11.86

#### **Table 17.**

*Response table for mean.*

**Figure 1.** *Main effect plot for S/N ratio: BW.*

**Figure 2.** *Main effect plot for mean: BW.*

geometry expressed as a function of peak current, base current, pulse frequency and pulse on time as given in Eq. (3). The predicted result as per the regression equation is shown in **Table 20**. After that % error between predicted value and experimental value is obtained as given in **Table 21** [10].

*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter DOI: http://dx.doi.org/10.5772/intechopen.93974*


#### **Table 18.**

*Optimum parameter for bead width.*


#### **Table 19.**

*Confirmatory results for bead width.*


geometry expressed as a function of peak current, base current, pulse frequency and pulse on time as given in Eq. (3). The predicted result as per the regression equation is shown in **Table 20**. After that % error between predicted value and

experimental value is obtained as given in **Table 21** [10].

**Level Peak**

**Table 17.**

**Figure 1.**

**Figure 2.**

**178**

*Main effect plot for mean: BW.*

*Main effect plot for S/N ratio: BW.*

*Response table for mean.*

**current (P)**

**Base current (B)**

*Quality Control - Intelligent Manufacturing, Robust Design and Charts*

 2.561 2.745 2.977 2.672 2.683 2.861 2.741 3.027 2.700 2.768 2.654 2.755 3.029 2.801 3.068 2.720 3.152 2.950 2.685 2.951 Delta 0.591 0.205 0.414 0.355 Rank 1 4 2 3

**Pulse frequency (F)**

**Pulse on time (%)**


Bead width mm ð Þ¼ 2*:*825 � 0*:*264 peak current\_140 � 0*:*142 peak current\_150

**Source DF Adj SS Adj MS F P % contribution** Peak current 4 1.2702 0.31754 0.97 0.475 24.42 % Base current 4 0.1357 0.03393 0.10 0.978 2.61 % Pulse frequency 4 0.6903 0.17256 0.53 0.720 13.27 % Pulse on time 4 0.4801 0.12002 0.37 0.827 9.23 %

*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter*

ANOVA test the hypothesis that the means of two or more population are equal. AVOVA is a computational technique to quantitatively estimate the contribution that each parameter makes on the overall observed response. By using ANOVA percentage contribution of each parameter is obtained as shown in **Table 22**.

In this Taguchi approach is applied to determine the most influencing process parameter which effect the output response i.e BW (Bead Width). By using Minitab 18 statistical analysis software all possible combination of all input process parameter has been established Using L25 orthogonal array experiment has been conducted to determine S/N ratio. The response table is developed to determine the rank of each parameter. Main effect plot obtained from Minitab 18 statistical analysis software is used to determine the most influencing process parameter and their significant level. Optimum parameter for bead width is 180A peak current, 100A base current, 125 Hz pulse frequency and 40% pulse on time. The confirmatory test has

<sup>5</sup>*:*<sup>2012</sup> X 100 ¼ 24.42 %

<sup>5</sup>*:*<sup>2012</sup> X 100 ¼2.67 %

<sup>5</sup>*:*<sup>2012</sup> X 100 ¼13.27 %

<sup>5</sup>*:*<sup>2012</sup> X 100 ¼ 9.230%

**4.9 ANOVA for all the response**

Error 8 2.6249 0.32812

Total 24 5.2012

*DOI: http://dx.doi.org/10.5772/intechopen.93974*

**Table 22.**

*ANOVA for bead width.*

1.Peak Current <sup>1</sup>*:*<sup>2702</sup>

2.Base current <sup>0</sup>*:*<sup>1357</sup>

3.Pulse frequency <sup>0</sup>*:*<sup>6943</sup>

4.Pulse on time <sup>0</sup>*:*<sup>4801</sup>

**5. Conclusion**

**181**

� 0*:*125 peak current\_160 þ 0*:*204 peak current\_170 þ 0*:*327 peak current\_180 � 0*:*080 base current\_60 þ 0*:*036 base current\_70 � 0*:*057 base current\_80 � 0*:*024 base current\_90 þ 0*:*125 base current\_100 þ 0*:*152 pulse frequency\_50 � 0*:*084 pulse frequency\_75 � 0*:*171 pulse frequency\_100 þ 0*:*243 pulse frequency\_125 � 0*:*140 pulse frequency\_150 � 0*:*153 pulse on time\_35 þ 0*:*202 pulse on time\_40 � 0*:*070 pulse on time\_45 � 0*:*105 pulse on time\_50 þ 0*:*126 pulse on time\_55

(3)

#### **Table 20.**

*Predicted result from the regression equation.*


#### **Table 21.**

*Percentage error between predicted & experimental results.*

*Application of Taguchi Method in Optimization of Pulsed TIG Welding Process Parameter DOI: http://dx.doi.org/10.5772/intechopen.93974*


**Table 22.** *ANOVA for bead width.*

**Exp. no.**

**Table 20.**

**Exp. no.**

**Table 21.**

**180**

*Percentage error between predicted & experimental results.*

*Predicted result from the regression equation.*

**Process parameter 1**

**Process parameter 1**

**P B F T BW**

**P B F T BW**

 170 100 100 35 2.78 180 60 150 50 2.46 180 70 50 55 3.68 180 80 75 35 3.17 180 90 100 40 2.69 180 100 125 45 3.91

*Quality Control - Intelligent Manufacturing, Robust Design and Charts*

Bead width mm ð Þ¼ 2*:*825 � 0*:*264 peak current\_140 � 0*:*142 peak current\_150 � 0*:*125 peak current\_160 þ 0*:*204 peak current\_170 þ 0*:*327 peak current\_180 � 0*:*080 base current\_60 þ 0*:*036 base current\_70 � 0*:*057 base current\_80 � 0*:*024 base current\_90 þ 0*:*125 base current\_100 þ 0*:*152 pulse frequency\_50 � 0*:*084 pulse frequency\_75 � 0*:*171 pulse frequency\_100 þ 0*:*243 pulse frequency\_125 � 0*:*140 pulse frequency\_150 � 0*:*153 pulse on time\_35 þ 0*:*202 pulse on time\_40 � 0*:*070 pulse on time\_45 � 0*:*105 pulse on time\_50 þ 0*:*126 pulse on time\_55 (3)

#### **4.9 ANOVA for all the response**

ANOVA test the hypothesis that the means of two or more population are equal. AVOVA is a computational technique to quantitatively estimate the contribution that each parameter makes on the overall observed response. By using ANOVA percentage contribution of each parameter is obtained as shown in **Table 22**.

1.Peak Current <sup>1</sup>*:*<sup>2702</sup> <sup>5</sup>*:*<sup>2012</sup> X 100 ¼ 24.42 % 2.Base current <sup>0</sup>*:*<sup>1357</sup> <sup>5</sup>*:*<sup>2012</sup> X 100 ¼2.67 % 3.Pulse frequency <sup>0</sup>*:*<sup>6943</sup> <sup>5</sup>*:*<sup>2012</sup> X 100 ¼13.27 % 4.Pulse on time <sup>0</sup>*:*<sup>4801</sup> <sup>5</sup>*:*<sup>2012</sup> X 100 ¼ 9.230%
