## 3 Results and Discussion
### Electrical Properties  
Figure 10 contains the temperature dependences of specific electrical resistance \(\rho\) for the samples of different compositions after HPT with various numbers of revolutions.  
The plots of \(\rho\)(T) show the same trend of specific electrical resistance of the matrix alloy and the composite: deformation-induced growth of the electrical resistance and reduced dependence of resistance on temperature (a lower angle of the slope). Values of electrical resistance at room temperature, 293 K, were chosen for a comparative analysis of electrical resistance of the matrix alloy and the composite and its evolution with the number of revolutions during HPT (Table 3). The data indicate that deformation with n = 10 induced the highest increase in electrical resistance in all the samples. The values of specific electrical resistance were used to calculate the specific electrical conductivity \(\sigma\) of the composites in absolute units \(\sigma=1/\rho\) and in the relative units of the IACS international standard:  
\[\text{IACS}=\sigma_{\text{AlFeGn}}/\sigma_{\text{Cu}}\ (\times\ 100\%),\]  
where \(\sigma_{\text{Cu}}\) = 58 MS/m (Table 3).  
Based on the analysis of the structure of the deformed samples, it can be concluded that the growth in their specific electrical resistance and the decrease in their conductivity may be related to the formation of defects and to the deformation-induced dissolution of iron aluminides, which result in the formation of a supersaturated Al solid solution. Obviously, the increase in the iron content in the Alsolid solution, which accompanies the intensification of intermetallic phase dissolution, will increase resistance and decrease conductivity. According to the calculations of the lattice perioda, the supersaturation of the Al solid solution reaches its maximum in the AlFeGn composite after n = 10 (Table 2). Assuming that, with all else being equal (with respect to the degree of defective of all  
Figure 10: Specific electrical resistance of the matrix alloy (**a**) and the composite (**b**) after HPT with various numbers of revolutions vs. temperature.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & \multicolumn{2}{c}{\(\rho\)**, **Oh-m-cm**} & \multicolumn{2}{c}{\(\sigma\)**, **MS/m**} & \multicolumn{2}{c}{**IACS, \%**} \\ \cline{2-7}  & **AlFe** & **AlFeGn** & **AlFe** & **AlFeGn** & **AlFe** & **AlFeGn** \\ \hline
0 & 3.7184 \(\pm\) 0.0027 & 3.3255 \(\pm\) 0.0073 & 26.8933 & 30.0704 & 46 & 52 \\ \hline
5 & 3.9662 \(\pm\) 0.0026 & 3.8235 \(\pm\) 0.0026 & 25.2129 & 26.1541 & 43 & 45 \\ \hline
10 & 6.9797 \(\pm\) 0.0029 & 6.1212 \(\pm\) 0.0034 & 14.3273 & 16.3367 & 24 & 28 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Electrical properties of the matrix alloy and the composite at room temperature.  
the samples after n = 10), the different values of conductivity are only due to the Fe content in the solid solution, the composite should have a lower conductivity compared to the matrix alloy. The values for the conductivity given in Table 3 indicate the opposite: the conductivity of the composite is higher than the conductivity of the matrix alloy both in the as-cast and in the deformed state. Thus, it can be concluded that the addition of graphene to the as-cast alloy as well as the HPT alloy not only fully compensated for the drop in specific electrical conductivity but also increased its value compared to that of the matrix alloy. The difference in electrical conductivity is 6% in the as-cast state and 3% IACS after HPT.