Synthesis of die-castable nano-particle reinforced aluminum matrix composite materials by in-situ gas-liquid reactions

Nano-particle reinforced aluminum matrix composites areattractive engineering materials for many automotive andaerospace applications because they exhibit numerousdesirable mechanical and thermal properties, such ashigh specific strength, hardness, stiffness, and resistanceto creep and thermal degradation. Unfortunately, makingthese materials is not easy and most of the methodsthat have been developed so far for their synthesis areeither not robust, inefficient, or not cost effective. In thispublication, we report on the synthesis of die-castablealuminum-aluminum nitride nano-composite materialsby the reaction of a nitrogen-containing gas with moltenaluminum-lithium alloy. Specifically, we report on the effectof (1) the lithium content of the alloy, (2) the compositionof the reactive gas, and (3) the reaction time on (a) theamount, (b) the average size, and (c) the average clustersize of the aluminum nitride reinforcing particles; as wellas (d) the hardness and (e) the thermal stability of thecomposite material.