In this study, the effects of cutting speed and feed rate on the roughness parameters R_a, R_z, R_sk, R_ku, R_pk, R_vk, and A₂ were examined during machining with coated carbide tools in a dry environment. The authors introduced the R_vk/R_pk ratio, a coefficient that facilitates a simpler evaluation of surface wear resistance. Specifically, if this ratio is greater than 1, the surface is more wear-resistant, while values less than 1 indicate a higher tendency for surface wear. The Taguchi OA method was used to analyze and identify the significance of technological parameters on output characteristics. Based on the results, it was established that feed rate has the greatest impact on all output characteristics. The highest cutting force was measured at a cutting speed of 60 m/min and a feed rate of 0.15 mm/rev, attributed to the fact that at lower cutting speeds, the base material does not soften while the cross-sectional area of the chip increases. To achieve the lowest R_a and R_z surface roughness, a cutting speed of 100 m/min and a feed rate of 0.05 mm/rev are recommended. If the goal is to enhance surface wear resistance and improve oil retention capability, machining with a cutting speed of 80–100 m/min and a feed rate of 0.15 mm/rev is advisable, as the coarser machining increases both the R_vk/R_pk ratio and the oil-retaining pocket size, which together improve the wear resistance of the machined surface.

This study investigates the effects of the rake angle and clearance angle of custom-manufactured HSS-E Co5 high-speed steel cutting tools on the F_c main cutting force, the F_p passive force component, the Ra and Rz surface roughness parameters, and chip morphology during orthogonal free cutting of EN AW-7075-T6 aluminum alloy. A dedicated experimental fixture was designed and manufactured for the measurements, providing highly accurate depth-of-cut adjustment and ensuring excellent repeatability of the experiments. A full-factorial experimental design was employed, in which the rake angle varied between 0° and 30°, while the clearance angle ranged from 5° to 15°. Three independent cutting trials were performed for each tool geometry. The results showed that increasing the rake angle significantly reduced both the main cutting force (F_c) and the passive force (F_p), whereas increasing the clearance angle resulted in higher force values. Surface roughness analysis revealed that the clearance angle was the dominant factor affecting surface quality. The highest Ra and Rz values were measured at a clearance angle of 15°. Two-way analysis of variance confirmed that the rake angle, the clearance angle, and their interaction had statistically significant effects on the F_c, F_p, Ra, and Rz results. The clearance angle exhibited the strongest effect on F_c, Ra, and Rz, whereas the rake angle had the strongest influence on F_p. Chip morphology observations demonstrated that larger rake angles promoted smoother chip flow and reduced chip compression, while smaller rake angles resulted in thicker and more tightly curled chips. Overall, the combination of larger rake angles and smaller clearance angles provided the most favorable machining conditions, resulting in lower cutting forces, improved chip formation, and enhanced surface quality.

Nowadays, aluminum alloys play a dominant role in the automotive industry due to their many favorable properties. A disadvantage of these components is that high-strength metal screw connections cause corrosive chemical processes, which can lead to damage and destruction of the aluminum casting during assembly. If it is not possible to replace the component, for example in the case of high-value vintage vehicles, then it is necessary to manufacture a new component or develop some kind of repair technology. In the case of manufacturing a new component, it is necessary to model the old damaged component and then manufacture it in a machine shop using some kind of cutting process, which is a very expensive method. This article presents the repair of an A360 aluminum alloy generator bracket using argon tungsten arc welding followed by fabrication technology post-processing, which is a cost-effective way to repair such components.