In-Situ Synthesis of Aluminum Matrix Composite from Al-NiO System by Mechanical Alloying

In this paper, Al-based composites reinforced by Alumina and Al-Ni intermetallic compounds have been successfully fabricated by mechanical alloying technique. The intermetallic phase, i.e., NiAl, NiAl3, Ni2Al3, as well as Alumina, were formed in the aluminum matrix by in situ solid-state reactions between pure Al and NiO powders. The effects of NiO content (7-10-13 vol%) on the characteristics of the fabricated composites were examined, the hardness, wear properties, phase constituent, and composite microstructure with different NiO content in particular. The results showed that the addition of NiO to Al increases the formation of Al-Ni system intermetallic compounds and enhance the surface hardness. Further, it is ascertained that Al-10 vol% NiO nanocomposite has better wear properties in comparison with samples with 7 and 13 vol% NiO due to the better matrix integrity and reinforcement distribution in the Al matrix.