## 3 Results and Discussion
### Anova  
Table 5 shows the degrees of significance in percentages of the variables as a function of the F-value and the \(p\)-value. Figure 13 shows the main effects graph for each variable. For \(T\) (Figure 13a), the parameters that have significance in the process are TFR and WP with F-values of 18.31 and 9.87, respectively. This is shown in the graph where the slope of TFR indicates the degree of influence on the process. In addition, TFR ranges from the lowest to the highest values in the process. WP shows a greater degree of influence on defect formation when the selected pressure is in the range 380-500 MPa, which causes a decrease in the measured taper angle from approximately 1.65\({}^{\circ}\) to 1.40\({}^{\circ}\). Finally, AMFR does not seem to show significance in \(T\) formation. However, it is observed that the defects are lower for 340 g/min, as determined in the previous section. As for the analysis of different roughness zones, Figure 13b-d shows the main effects graphs for Zone 1, Zone 2, and Zone 3, respectively. The degree of influence of each parameter is described below. Figure 12: (a) SEM image. Jet outlet. Test 7. WP = 500 = MPa; AMFR = 450 g/min; TFR = 100 mm/min; (b) SEM image. Jet outlet. Test 21. WP = 250 MPa; AMFR = 170 g/min; TFR = 500 mm/min; (c) Detail of grooves plowed by abrasive grains. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multicolumn{3}{c}{**TFR**} & \multicolumn{5}{c}{**WP**} & \multicolumn{5}{c}{**AMFR**} \\ \hline
**Variable** & **F** & \(p\) & **\%** & **Variable** & **F** & \(p\) & **\%** & **Variable** & **F** & \(p\) & **\%** \\ \hline T & 18.31 & 0.000 & **50.40** & T & 9.87 & 0.001 & **27.17** & T & 3.20 & 0.066 & 8.82 \\ Zone 1 & 6.29 & 0.008 & 32.77 & Zone 1 & 2.66 & 0.095 & 13.85 & Zone 1 & 0.24 & 0.787 & 1.26 \\ Zone 2 & 6.29 & 0.008 & 31.79 & Zone 2 & 3.28 & 0.059 & 14.89 & Zone 2 & 0.21 & 0.813 & 1.06 \\ Zone 3 & 14.20 & 0.000 & **47.71** & Zone 3 & 4.75 & 0.021 & 15.96 & Zone 3 & 0.81 & 0.457 & 2.74 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Analysis of variance (ANOVA) results of the evaluated variables: traverse feed rating (TFR), working pressure (WP), abrasive mass flow rate (AMFR). Zone 1. There are no significant parameters in this area. However, the degree of influence of the factor F on the process was analyzed. Thus, the parameter with the most influence on the formation of roughness in this zone is TFR, followed by WP and AMFR. Indeed, TFR shows an upward trend in the graph, over the range 300-500 mm/min. In this range, there is an average increase of about 8 \(\upmu\)m to 20 \(\upmu\)m. WP shows variable behavior depending on the selected level. An intermediate level provides a slightly lower roughness than a high level, which means that in roughness formation this parameter loses significance as it reaches a certain limit with sufficient kinetic energy. AMFR seems to have no influence on the process, although an increase in the level of abrasive produces a slight decrease, as predicted in the overall analysis of results. Zone 2. In this zone, both the influence of parameters and the degree of significance are similar to those in Zone 1, although it should be noted that the roughness experiences a slight average decrease over the process. This phenomenon can be seen in the intermediate line that appears in the graph where the average value obtained is shown, being, in this case, less than 10 \(\upmu\)m. The analysis in Section 3.1.2 revealed that IDR exists. However, its size is small due to the high hardness of the material. It is characterized by the localized detachment of small amounts of material, as detected by SEM analysis. Thus, the differences between Zone 1 and Zone 2 are mainly attributed to differences in measurement caused by this defect. Zone 3. The significant parameter is TFR with an F-value of 14.20. This is shown in the main effects graph with a high slope for the entire range of levels from 100 mm/min to 500 mm/min.