# Comparison of the Wear of Toroidal and Spherical Cutters in Milling and the Impact of Corrosion
## 3 Experimental Results
Spherical cutters, due to the point (or linear, depending on the depth of cut) contact of the spherical edge with the workpiece, increase the axial component of the force at large angles. This leads to greater pressure on the cutting edge, amplifying abrasive wear and the risk of microcracking. Studies show that spherical cutters can generate 15-25% higher cutting forces in the axial direction compared to toroidal cutters under similar conditions. After the completion of the initial measurements, the 6 milling cutters subjected to analysis were kept in an ambient environment, characterized by relatively constant temperature and humidity fluctuations, without being involved in processing processes, manipulated, or subjected to technical interventions. As for the temperature ranges, they are between 10 \({}^{\circ}\)C and 22 \({}^{\circ}\)C without exposure to corrosion gases, with humidity varying between 35% and 45%. Also, no corrosion protection measures were applied during exposure. These cutters were left in a state of inactivity for 5 years, during which the ambient conditions varied naturally. Currently, the wear of the cutting part will be measured again, using the same measurement methods and conditions applied at the time of the initial assessment, in order to allow an objective and precise comparison of the evolution of the wear phenomenon. The evolution of the condition of the tool cutting part used for machining at a 15\({}^{\circ}\) inclination angle is shown in Figure 10. Figure 10b shows the wear of the spherical cutter with a maximum length of 2.426 mm and a maximum width of 0.128 mm, with a wear area of 0.31419 mm\({}^{2}\). In Figure 10a, the wear of the toroidal cutter is shown as having a maximum length of 3.660 mm and a maximum width of 0.234 mm, resulting in a wear area of 0.38008 mm\({}^{2}\). Figure 9: Graphical representation of comparative wear values between toroidal and ball milling cutters. Changes in the wear of the cutting part of the tools used in machining processes at the 35\({}^{\circ}\) tilt angle are shown in detail in Figure 11. Figure 11b illustrates the wear of the spherical cutter, which has a maximum length of 4.252 mm and a maximum width of 0.149 mm, resulting in a wear area of 0.43704 mm\({}^{2}\). Similarly, Figure 11a details the wear of the toroidal cutter, which has a maximum length of 3.767 mm and a maximum width of 0.430 mm, with a wear area of 0.57925 mm\({}^{2}\). The wear transformations of the tool cutting part used in machining processes at the 55\({}^{\circ}\) tilt angle are shown in detail in Figure 12. In Figure 12b, the wear of the spherical cutter is illustrated, which records a maximum length of 4.252 mm and a maximum width of 0.149 mm, resulting in a wear area of 0.43704 mm\({}^{2}\). In the same figure, in Figure 12a, the wear of the toroidal cutter is highlighted, which has a maximum length of 3.767 mm and a maximum width of 0.430 mm, and the wear area is calculated at 0.57925 mm\({}^{2}\). This data allows a detailed comparison of the changes suffered by the two types of cutters, highlighting values of initial wear and values of wear affected by corrosion. Corrosion of tools stored for five years under ambient conditions (10-22 \({}^{\circ}\)C, 35-45% humidity) led to an increase in the area of worn surfaces, according to the measurements made and presented in Figure 5:0 This analysis examines the mechanisms of corrosion, the effects on worn surfaces, and the nature of the process (oxidation). In the absence of  
Figure 5:1 Wear Evolution of Spherical and Toroidal Milling Cutters Used in Machining with 35\({}^{\circ}\) Tilt Angle After Five Years. (**a**). Toroidal milling; (**b**). Spherical milling. Figure 5:2 Wear Evolution of Spherical and Toroidal Milling Cutters Used in Machining with a 55\({}^{\circ}\) Angle of Inclination After Five Years. (**a**). Toroidal milling; (**b**). Spherical milling. Figure 5:3 Evolution of wear of spherical and toroidal cutters used in machining with a 15\({}^{\circ}\) angle of inclination after five years. (**a**).