## 4 Conclusions  
An Al-Mg metal-matrix composite was obtained via severe plastic deformation using high-pressure torsion at 5 GPa followed by annealing at a temperature of 275 \({}^{\circ}\)C. SEM, EDX and XRD studies showed that interlayers corresponding to the Al\({}_{3}\)Mg\({}_{2}\) and Al\({}_{12}\)Mg\({}_{17}\) intermetallic phases were formed at the Al and Mg interfaces. The sputtering yield of the Al\({}_{3}\)Mg\({}_{2}\) phase was found to be 2.2 atom/ion, while the sputtering yield of the Al\({}_{12}\)Mg\({}_{17}\) phase was found to be 1.9 at/ion, which is lower than those of Al (2 at/ion) and Mg (2.6 at/ion). The sputtering yield of the Al\({}_{12}\)Mg\({}_{17}\) phase did not follow the additivity rule for its constituent metals, as opposed to the Al\({}_{3}\)Mg\({}_{2}\) phase. To explain the differences in the sputtering yields, DFT-based simulations were used to calculate the surface-binding energy values for Al, Mg and the Al\({}_{12}\)Mg\({}_{17}\) phase. The values of the surface-binding energies of Al and Mg were in a range of 3.40-3.84 eV and 1.56-1.57 eV, respectively. The surface binding energy for the Al\({}_{12}\)Mg\({}_{17}\) phase with an Al atom removed from its surface was found to be in a range of 3.90-4.02 eV, and in a range of 1.53-1.71 eV with a Mg atom being removed. Optical microscopy analysis revealed that the Al\({}_{3}\)Mg\({}_{2}\) phase with a cellular wall surface morphology, which formed due to its irradiation with argon ions with an energy of 5 keV, had a high absorption capacity in the visible light spectrum relative to Al, Mg and the Al\({}_{12}\)Mg\({}_{17}\) phase. The WF of the obtained Al-Mg nanostructured composite was found to be 4 eV. This value was in a range between the WF values of Al (4.3 eV) and Mg (3.6 eV); i.e., the additivity rule was preserved. Using DFT-based simulations, the WF of the Al\({}_{12}\)Mg\({}_{17}\) phase was determined; its value was found to be in a range of 3.63-3.75 eV, which agrees with the additivity rule. Therefore, the intermetallic alloy based on Al\({}_{12}\)Mg\({}_{17}\), with its relatively low sputtering yield and WF, was found to be promising as a cathode material for various gas-discharge devices, plasma installations, ion sources, sputtering systems, etc. The intermetallic alloy based on Al\({}_{3}\)Mg\({}_{2}\) with a modified surface was found to be a promising optical- and acoustic-absorbing material.  
Conceptualization, R.K.K., G.F.K., K.S.N. and R.R.M.; methodology, R.U.S., R.R.T. and Y.M.Y.; validation, G.R.K., G.F.K. and K.S.N.; formal analysis, A.A.K. and E.A.K.; investigation, R.K.K., A.A.K., G.R.K., R.U.S. and R.R.T.; writing--original draft preparation, R.K.K. writing--review and editing A.A.K., G.F.K. and E.A.K.; visualization, R.U.S.; supervision, R.R.M.; project administration, G.F.K. All authors have read and agreed to the published version of the manuscript.  
The present work was accomplished according to the state assignment of IMSP RAS. SEM studies were performed using the equipment of the Center for Shared Access \"Structural and Physicochemical Investigations of Materials\" at the Institute for Metal Superplasticity Problems of the Russian Academy of Sciences. E.A.K. acknowledges the support of Grant NSh-4320.2022.1.2 from the President of the Russian Federation for the state support of young Russian scientists--candidates of sciences and doctors of sciences. A.A.K. is grateful for financial support from the Ministry of Science and Higher Education of the Russian Federation within the framework of the state task of the UUST (No. 075-03-2023-119) of the youth research laboratory \"Metals and Alloys under Extreme Impacts\". DFT simulations were carried out using the equipment of the shared research facilities of the Joint Supercomputer Center of the Russian Academy of Sciences.  
Not applicable.  
The authors are grateful to [PERSON] (University of Strathclyde, Glasgow, UK) for assistance in manuscript preparation (English editing).  
The authors declare no conflict of interest.