Al-based composites reinforced with AlB2, AlN and BN phases: Experimental and theoretical studies

The influence of reinforcing AlN, AlB2 and BN phases, either individually or in combination, on the mechanical properties of Al-based composites fabricated via reactive ball milling of Al/BN, Al/B, and Al/Li3N powder mixtures, followed by their spark plasma sintering (SPS) was studied. An increase in tensile strength by 135% (25 °C) and 185% (500 °C) compared to pure Al was achieved in the Al/BN composites where BN, AlN, and AlB2 phases simultaneously formed. Density functional theory (DFT) calculations of the interface strength between Al and formed phases supported the experimental data. The obtained results demonstrated that the combination of reactive ball milling and SPS is a promising technique allowing for the formation of reinforcing phases from source materials.