## 3 Results and Discussion
### Surface Structure Modification as a Result of Ion Irradiation  
As a result of ion irradiation, the initially smooth surface of the Al-Mg sample was transformed. An etched Al matrix and etched isolated Mg inclusions were observed on the sample surface (Figure 3). Mg inclusions were found to be more susceptible to etching; i.e., more deep etching was observed compared with the Al matrix. Figure 3: SEM image (SE mode) of the surface of the Al-Mg nanostructured composite after HPT and annealing following ion irradiation. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{1}{c}{**Metal**} & \multicolumn{2}{c}{**Our Calculated WF, eV**} & \multicolumn{2}{c}{**Other Theoretical Results of**} & \multicolumn{2}{c}{**Experimental Results of**} \\  & & & **WF, eV [22]** & **WF, eV [22]** \\ \hline \multirow{4}{*}{Al} & (001) & 4.20 & 4.41, 4.38 & 4.41 \\  & (101) & 4.21 & 4.08, 4.30 & 4.28 \\  & (111) & 4.08 & 4.36, 4.25 & 4.24 \\ \hline \multirow{2}{*}{Al\({}_{12}\)Mg\({}_{17}\)} & (001)\(\rightarrow\)(0001) & 3.63 & - & - \\  & (111)\(\rightarrow\)(11-21) & 3.75 & - & - \\ \hline \multirow{2}{*}{Al\({}_{30}\)Mg\({}_{23}\)} & (001)\(\rightarrow\)(0001) & 3.77 & - & - \\  & (111)\(\rightarrow\)(11-21) & 3.85 & - & - \\ \hline \multirow{2}{*}{Mg} & (001)\(\rightarrow\)(0001) & 3.6 & 3.79 & 3.65 \(\div\) 3.84 \\  & (101)\(\rightarrow\)(10-11) & 3.39 & 3.70 \(\div\) 3.80 & – \\ \cline{1-1}  & (111)\(\rightarrow\)(11-21) & 3.67 & 3.56 \(\div\) 3.68 & 3.66 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The values of the electron WFs of the Al, Mg and Al\({}_{12}\)Mg\({}_{17}\) and Al\({}_{30}\)Mg\({}_{23}\) intermetallic phases calculated via the DFT method. Different morphologies of the Al and Mg areas and interlayers of the Al\({}_{3}\)Mg\({}_{2}\) and Al\({}_{12}\)Mg\({}_{17}\) intermetallic phases were revealed via SEM at higher magnifications (Figure 4). Etching pits with a diameter of up to 10 \(\upmu\)m formed on the Al surface. Cones with a concentration of 100-200 cones/\(\upmu\)m\({}^{2}\) were formed on the Mg surface. As a result of irradiation, a relief similar to a cellular wall structure was formed on the surface corresponding to the Al\({}_{3}\)Mg\({}_{2}\) intermetallic phase. Within the cellular wall structure, curved structures similar to fibers were located. The interlayer corresponding to the Al\({}_{12}\)Mg\({}_{17}\) phase had a smooth surface after irradiation. On the lateral side of the Al\({}_{12}\)Mg\({}_{17}\) phase interlayer, fibers oriented along the plane of the sample were observed. The formation of various surface morphologies during ion irradiation is known to depend on the irradiation conditions, i.e., dose, fluence and ion energy and the nature of the material and its temperature during irradiation. The simultaneous formation of etch pits on the Al surface and cones on the Mg surface under the same irradiation conditions was the result of the difference in the crystal structure and lattice type of these metals [45]. The difference in the relief formed as a result of ion irradiation on the surface of the interlayers, which corresponded to the Al\({}_{3}\)Mg\({}_{2}\) and Al\({}_{12}\)Mg\({}_{17}\) intermetallic phases, can also be associated with the difference in the crystal structure and lattice type of these phases. Figure 5 shows the SEM images combined with the EDX map and the element composition profile of the Al-Mg sample surface area after irradiation (Figure 4). Given the measured profiles and the corresponding chemical compositions, it can be seen that the etched areas with different reliefs on the surface of the irradiated composite sample corresponded to Al (line 1), Mg (line 4) and the interlayers of the Al\({}_{3}\)Mg\({}_{2}\) (line 2) and Al\({}_{12}\)Mg\({}_{17}\) (line 3) intermetallic phases. As a result of a detailed analysis of the interlayer corresponding to the Al\({}_{3}\)Mg\({}_{2}\) intermetallic phase, the wall chemical composition of the cellular wall structure was found to be predominantly Al.