Investigation of Microstructure, Hardness and Wear Properties of Hybrid Nanocomposites with Al2024 Matrix and Low Contents of B4C and h-BN Nanoparticles Produced by Mechanical Milling Assisted Hot Pressing

In this study, Al2024-based hybrid nanocomposites with the reinforcement of nano-sized B4C and h-BN particles have been fabricated by powder metallurgy method assisted mechanical milling and hot pressing. The effect of h-BN content on microstructure, density, hardness and wear behavior of Al2024/B4C/h-BN hybrid nanocomposite was examined. Scanning electron microscope (SEM) with energy dispersive spectrum were used for microstructural evolution and worn surface characterization of fabricated sample. SEM images showed that B4C nanoparticles were distributed uniformly in the Al2024 matrix while h-BN nanoparticles accumulated at the particle boundaries in the microstructure. While the relative density values decreased with the increase of the h-BN nanoparticle reinforcement content, an increase in the porosity values was detected for the hybrid nanocomposite samples. Additionally, in hybrid composites with Al2024 matrix containing the same amount of B4C additive, 2% h-BN additive provided 75% lower wear loss than 1% h-BN additive at 40 N loading condition. So, the addition of h-BN nanoparticles significantly improved the wear resistance of hybrid nanocomposite.

Automated summary

In this study, Al2024-based hybrid nanocomposites reinforced with nano-sized B4C and h-BN particles were fabricated. The addition of h-BN nanoparticles significantly improved the wear resistance of the hybrid nanocomposite, with B4C and h-BN particles showing distinct distribution patterns in the microstructure.