## 5 Cutting Tool Characterization Results
#### EDS Analysis  
The chemical composition of the adhered material on the rake face and flank of the CNMG and SCGN inserts was checked through an EDS analysis. The concentration of each element was measured by the intensities of peaks, which was expressed in an atomic percentage, as shown in Table 4. The ceramic tools showed abrasion followed by adhesion as the main wear mechanisms according to the microscopy analysis. The EDS analysis on the surface of the SCGN12F insert shows a significant amount of Fe, Mn, Si, and C that confirmed the presence of the adhered material. However, the atomic percentage of the chemical elements found on wear zones of SCGN tools were not decisive for validating the phase composition of oxides as FeO or SiO\({}_{2}\). The ceramic tool cut at a speed of 1115 m/min, resulting in a temperature increase of up to 1000 \({}^{\circ}\)C due to the constant and rapid interaction between the tool and the chip. Under these conditions, a chemical oxidation reaction can occur between the Fe, the ceramic insert, and the oxidation during the cutting process. This too could explain the generation of notch wear observed in the SCGN tools [29; 30; 37].  
The oxygen was found in all wear regions, mainly a large percentage on the flank of CNMG5 and CNMG12 inserts. The oxygen was formed during oxidation in air at a high temperature in the cutting zone, which may contribute to tool wear. For the case of coated-carbide tools, the inspection on the rake face of CNMG5R and CNMG12R indicated a higher concentration of O, Al, and Fe. In the case of the CNMG5R insert, the EDS analysis enabled the phase composition that was identified as alumina (Al\({}_{2}\)O\({}_{3}\)). The atomic percentage of Al and O was similar to the theoretical amount calculated for each element of the chemical form of alumina, considering the balance with the other elements that are shown in Table 4. Similarly, on the rake face of CNMG12, Fe and O were found with a quantity of 15.68 at.% and 69.83 at.%, respectively. These quantities suggest the presence of the phase of FeO as a wear product, which confirmed our previous analysis that the adhesion on the rake face is the main wear mechanism. Compared with other work, the aluminum and iron oxidation too have been observed [38].  
In the Figure 9, a zinc peak can be seen in the EDS spectrum of the SCGN insert, which is unexpected because the certainty of amounts below \(\sim\)0.1 at.% is more complicated with this method. Additionally, this could be associated with the accidental contaminants or with that identified of a chemical element wrongly due to the content of the elements obtained through an automatic quantification EDS.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**SCGN5R**} & \multicolumn{2}{c}{**SCGN5F**} & \multicolumn{2}{c}{**SCGN12R**} & \multicolumn{2}{c}{**SCGN12F**} & \multicolumn{2}{c}{**CNMG5R**} & \multicolumn{2}{c}{**CNMG12R**} \\ \hline
**Element** & **at. (\%)** & **Element** & **at. (\%)** & **Element** & **at. (\%)** & **Element** & **at. (\%)** & **Element** & **at. (\%)** & **Element** & **at. (\%)** \\ \hline C & 41.61 & & & & C & 17.75 & C & 16.04 & C & 5.14 \\ N & 20.50 & C & 75.70 & N & 3.57 & Mg & 0.91 & O & 52.15 & O & 69.83 \\ O & 32.40 & O & 22.46 & O & 39.28 & Al & 5.46 & Al & 27.40 & Mg & 3.28 \\ Mg & 1.78 & Al & 0.11 & Mg & 1.68 & Si & 32.46 & Si & 0.63 & Al & 2.28 \\ Al & 0.21 & Si & 1.52 & Al & 0.02 & Mn & 15.45 & Fe & 3.65 & Si & 2.48 \\ Si & 2.75 & Zn & 0.21 & Si & 0.39 & Fe & 15.56 & Zn & 0.01 & Fe & 15.68 \\ Zn & 0.01 & & & Mo & 0.07 & Zn & 0.20 & Mo & 0.03 & Mo & 1.31 \\ Mo & 0.14 & & & & Mo & 1.90 & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: EDS analysis of rake face and flank wear.