# Comparison of the Wear of Toroidal and Spherical Cutters in Milling and the Impact of Corrosion
## 2 Experimental Data  
In the experimental phase, tool wear was monitored with the tool axis inclination angle--relative to the surface normal--used as the variable parameter. To investigate the surface type effect, five types of surfaces were machined, with 27 pieces per type. The test specimens are classified into five categories based on their physical characteristics. Experimentally, the processing of flat surfaces, the processing of spherical-convex surfaces, the processing of spherical-concave surfaces, the processing of cylindrical-convex surfaces, and the processing of cylindrical-concave surfaces will be carried out as illustrated in Figure 1.  
Each specimen has a width of 40 mm, a length of 40 mm, and a thickness of 20 mm, and is made of C45 carbon steel. To guarantee consistency in the data analysis, the same  
Figure 1: 3D shape of the 5 types of surfaces. materials were used for this investigation. Only the tool inclination angle was changed for each type of tool; the cutting parameters remained the same. The flat specimen (SPLN) is a surface on which a straight line can be applied perfectly in all directions; it retains its lateral dimensions, and as a result of processing, only its height changes. The spherical-concave surface (SFCV) is located in the upper part of the plate, symmetrically aligned with all four sides at the center of the square. The distance between the flat surface at its highest point is 5 mm, and the SFCV has a diameter of \(\mathcal{O}\)85 mm. The spherical-convex surface (SFCX) is represented by a recess in the upper part of the plate; this is positioned in the center of the plate, representing the distance of 5 mm from the maximum spherical recesses to the flat surface. The convex spherical shape has a diameter of \(\mathcal{O}\)85 mm. The cylindrical-concave surface (CICV) has a cylindrical height along the plate with a diameter of \(\mathcal{O}\)85 mm and a maximum height of 5 mm. The cylindrical-convex surface (CICX) is represented by a vertically positioned cylinder section with a depth of 5 mm, and its diameter is \(\mathcal{O}\)85 mm. The numerical control center used is the OKUMA MU-400 VA, a 5-axis machine tool. The two cutting tools used are: the JHP780160E2R400.0Z4-M64 toroidal milling cutter and the JS534160D1B.0Z4-NXT ball milling cutter. The toroidal milling cutter or corner milling cutter has a diameter of \(\mathcal{O}\)16 with a maximum cutting depth of 32 mm. Its radius at the corner is 4 mm with four teeth. This cutter is shown in Figure 2.  
The ball milling cutter has a diameter of \(\mathcal{O}\)16 with a maximum cutting depth of 48 mm. Its radius at the corner is 8 mm with four teeth. This cutter is shown in Figure 2.  
A total of three toroidal cutters and three spherical cutters were provided, analyzing the wear of the tool according to the angle at which it is used, so each tool will be used for only one type of inclination. As a result, each tool will process nine types of surfaces with different geometries, totaling a number of 45 surfaces processed at the same angle, these being the totality of the processes carried out with one cutter, this number of surfaces being generated following the application of the Taguchi method. Table 1 shows the surfaces processed with the toroidal tools according to the angle, Table 2 shows the surfaces processed with the spherical cutters according to the angle of inclination, and Figure 3 shows the processed specimens. Figure 2: Graphical representation of the two milling cutters. For a more precise measurement and a higher quality image, the MM1-200 microscope from Garant (Saint-Francois-de-la-Riviere-du-Sud, QC, Canada) was used, in the Faculty of