## 3 Results and Discussions
### Main Effect Plots for BW and BH  
The main effect plot shown in Figure 4 for BW explains the trend that was followed by varying the wire feed speed, travel speed and voltage of deposited material. The graph shows that there was a decrease in BW as travel speed increased. The reason was due to the speed at which the torch deposits the material. As the speed of the torch increased, there were fewer drops of molten metal being deposited, which resulted in a decrease in the BW of the weld bead [27]. Moreover, the trend for voltage shows an increase in BW of the weld bead. The reason for such an increase in width was due to the widening of the arc, which results in bigger droplets of molten metal being deposited [32]. Hence, a positive effect can be observed on the BW of the weld bead. Increasing the WFS has a negative effect on width as BW increases. The reason for such an increase in BW was due to the speed of wire coming out from the nozzle and the higher amount of material being deposited [33].  
Figure 5 showed the effect of WFS, travel speed and voltage on the BH of the deposited material. As it can be observed from Figure 5, there was a decrease in BH of the deposited material with the increase in travel speed. The reason behind such a trend is that a lower amount of material was deposited as the torch moved at a higher speed [34]. Because of the high travel speed, a negative effect can be observed on the BH of the deposited weld bead. This shows the effect of travel speed on bead geometry. In the same way, the BH decreases with the increase in voltage. The reason for such a decrease in BH was due to an increase in arc length and more deposition of the molten material [35]. Thus, with the spreading of those molten droplets, a decrease in BH can be observed. WFS also contributed to varying the bead geometry. When we increase the wire feed speed, the speed at which the wire comes out from the nozzle increases; hence, more material is deposited, which increases the BH of the weld bead [36].  
\begin{table}
\begin{tabular}{l l l l l l l} \hline \hline
**Source** & **DF** & **SS** & **MS** & **F** & **P** & **Significance** \\ \hline \multicolumn{6}{l}{**(a) BW**} \\ \hline
**Regression** & 9 & 19.8027 & 2.2003 & 93.24 & 0.000 & Significant \\
**Linear** & 3 & 17.8605 & 5.9535 & 252.29 & 0.000 & Significant \\
**Square** & 3 & 0.8874 & 0.2958 & 12.54 & 0.009 & Significant \\
**Interaction** & 3 & 1.0548 & 0.3516 & 14.90 & 0.006 & Significant \\
**Error** & 5 & 0.1180 & 0.0236 & & & \\
**Lack of fit** & 3 & 0.1107 & 0.0369 & 10.11 & 0.091 & Non-significant \\
**Pure error** & 2 & 0.0073 & 0.0037 & & & \\
**Total** & 14 & 19.9207 & & & & \\ \hline \multicolumn{6}{l}{**(b) BH**} \\ \hline
**Regression** & 9 & 12.3086 & 1.3676 & 23.41 & 0.000 & Significant \\
**Linear** & 3 & 11.9629 & 3.9876 & 68.25 & 0.000 & Significant \\
**Square** & 3 & 0.3341 & 0.1113 & 1.91 & 0.241 & Non-Significant \\
**Interaction** & 3 & 0.0116 & 0.0038 & 0.07 & 0.975 & Non-Significant \\
**Error** & 5 & 0.2921 & 0.0584 & & & \\
**Lack of fit** & 3 & 0.2769 & 0.0922 & 12.09 & 0.077 & Non-significant \\
**Pure error** & 2 & 0.0153 & 0.0076 & & & \\
**Total** & 14 & 12.6007 & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: ANOVA for (a) BW, and (b) BH.