Nanocomposites of aluminum alloy-MoSi2: Synthesis and characterization

Nanocomposites of AA 2024 aluminum alloy matrix reinforced with nano-sized MoSi2 particles were produced using mechanical alloying method followed by cold and hot pressing. Phase stability analysis, hardness, and room temperature compression tests of the composites were performed. In addition, absorb energy calculation and fracture behavior evaluation of the compression test specimens were carried out. The results indicated that the composite constituents exhibit good stability during the high temperature processing. The hardness and compressive strength of the composites show a steady increase for nano-sized MoSi2 particle contents up to 3vol.% and exceed values of 150 HB and 800MPa, respectively followed by a small drop at higher contents, most probably due to the particle agglomeration. Fractographic investigations of compression test specimens revealed that the failure mode of the composites with lower amount of reinforcement is mainly dimple ductile fracture while, with increasing the reinforcement amount, multiple cracking dominates.