**4. Conclusions**

This work is supposed to present a new approach in the study of the response of the AA7075 T651 alloy, which is widely used in the aeronautic industry, to different mechanical and chemical actions such as milling machining and the corrosion process. In this sense, this work deals with a study field where it hardly exists in the literature.

Considering typical processes used in aeronautics, dry face milling has been selected as the machining operation to perform on the flat samples (different combinations by fixing cutting speed and depth of cut and modifying the feed rate). The corrosive environment has been obtained by means of a salt fog chamber.

Different specific combinations of geometrical and technological cutting parameters are applied on flat specimens, which have been divided in two study groups. Samples belong to the second group and have been additionally exposed to a corrosive environment.

Based on the results obtained, it can be clearly seen as a relevant influence of both processes. On the one hand, whatever combination of milling parameters is applied, samples without a corrosion effect show an insignificant variation of their mechanical property values (2.37% in tensile strength

and 1.90% in yield strength). However, the elongation at break presents a great reduction (24.5%) that varies inversely with the feed rate increase. Consequently, a higher feed rate results in a greater fragility of the material.

On the other hand, analyzing specimens machined and subjected to corrosion, results reveal that this phenomenon provokes a strong influence on the elongation at break. The elongation reduction follows a similar tendency with respect to samples without corrosion, but these samples present an evident greater fragility with an average elongation of 10.80% in comparison to the 12.87% of the first ones. Therefore, it produced an additional significant reduction of the 19.17%.

It is necessary to point out that all these observations are only valid within the tested range of milling parameters.

**Author Contributions:** Conceptualization and Investigation, M.J.M., F.M. and M.J.C. Methodology, M.J.M., F.M., M.J.C. and G.C. Resources, M.J.H. Formal Analysis and Writing—Review & Editing, M.J.M. Writing—Original Draft Preparation, M.J.M. and F.M. Visualization and Supervision, F.M.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors want to thank the University of Malaga-Andalucia Tech, International Campus of Excellence, for its financial support of this paper.

**Conflicts of Interest:** The authors declare no conflict of interest.
