[en] Method of azide self-propagating high-temperature synthesis (SHS-Az), using sodium azide (NaN₃) as a nitriding reagent, was used for obtaining the nanopowder of aluminum nitride (AlN) from precursor that was sodium hexafluoroaluminate (Na₃AlF₆). The product of burning the mixture of Na₃AlF₆ + 3NaN₃ after water rinsing consisted of micro - and nanoparticles of AlN (65%) and the residue of salt Na₃AlF₆ (35%). This product of SHS-Az was mixed with copper powder and pressed into a briquette of nanopowdery master alloy Cu- 4%(65%AlN+35%Na₃AlF₆), which was successfully introduced into aluminium melt at a temperature of 850°C. The salt Na3AlF6 in the product of combustion played a role of flux during introducing into the aluminum melt and was not included in the final composition of the composite alloy. The microstructure of the obtained cast composite aluminum alloy with the calculated composition of Al-1.2%Cu-0.035%AlN showed that the reinforcing particles of AlN of different sizes, including nanoparticles, were distributed mainly along the grain boundaries of the aluminum alloy. (paper)