*2.1. Considered Workpiece Materials*

The considered workpiece materials were selected based on the requests that are usually performed to the company where the tool was validated. These are mainly aluminum alloys, although some requests are for parts made in a polymeric material. Regarding the considered aluminum alloys, these can be classified as "hard" aluminum alloys and "soft" aluminum alloys, indicating their hardness relative to one another. As for the "hard" aluminum alloys, AW7050, AW7075, AW2017, and AW2030 alloys were considered. Regarding the "soft" ones, the AW6082, AW6063, AW5083, and AW5724 were considered. The most relevant mechanical properties of these alloys can be observed in Table 2, these properties were taken from the material data sheet, provided by the material supplier.


**Table 2.** Mechanical properties values for the considered aluminum alloys.

In addition to the mentioned alloys, some polymers were also considered, as some parts made from these materials are requested by the company. These polymeric materials can also be divided into "hard", (e.g., PET and PVC) and "soft", (e.g., HD-PE and PTFE) plastics. Due to their properties, polymeric materials are usually easier to cut than metals; as such, the machining parameters selected for the machining of these parts are usually higher (namely feed rate and axial depth of cut). Taking these higher values as reference (100% of feed rate value is used for these materials), in Figure 4, the percentual values of feed rate and axial depth of cut can be seen for both "hard" and "soft" aluminum alloys and polymeric materials.

**Figure 4.** Variation of feed rate (**a**); and axial depth of cut (**b**) value, percentual, for the machining of soft and hard aluminum alloys and polymeric materials.

As can be observed in Figure 4, the machining parameter values are higher for softer materials, this will make the machining of these materials faster (given that the workpiece is the same). The variation in axial depth of cut is also dependent on the chosen value of radial depth of cut. This value is divided into three levels:

