Production of Al2024/h-BN nanocomposites with improved corrosion, wear and mechanical properties
Abdullah Hasan Karabacak, Aykut Çanakçı, Müslım Çelebı, Onur Güler, Sedat Alperen Tunç, Kürşat Alp Arpacı
Abstract
In this study, hexagonal boron nitride ( h -BN) reinforced Al-based metal matrix nanocomposites were successfully prepared using a powder metallurgy-assisted high-energy ball milling and vacuum-hot pressing process. Al2024 alloy and h -BN nano-powders (at 0, 2, 3, 4, and 5wt%) were milled for 8 h to produce Al2024/ h -BN nanocomposites. The effect of h -BN nanoparticle content on the microstructure, density, hardness, tensile strength , wear, and corrosion behavior of Al2024/ h -BN nanocomposites was investigated. It was observed that the h -BN powders in the Al2024/ h -BN nanocomposites were homogeneously distributed up to a content of 4 wt%, beyond which the h -BN aggregated at the grain boundaries due to excessive reinforcement. The uniform distribution of h -BN nanoparticles in the Al2024 matrix had a positive effect on the mechanical properties and wear and corrosion behavior of the Al2024/ h -BN nanocomposites. The results showed that the highest values of hardness and tensile strength were 126 HB and 299.72 MPa, respectively, in the 4 wt% h -BN reinforced sample. The wear volume loss decreased significantly as the h -BN reinforcement content increased up to 4 wt %. The corrosion experiment results showed that the corrosion resistance of the 4 wt % h-BN reinforced nanocomposite, which had the lowest polarization resistance of 15.22 Ω cm2, was almost 5 times higher than that of the unreinforced Al2024 alloy.