Effect of Addition of CNTxGnPyhBNz Ternary Hybrid Nanofillers on Mechanical Performance of Al Nanocomposites: A Comparative Study

This study addresses a significant knowledge gap in the development of aluminum-based hybrid nanocomposites by investigating the synergistic effects between one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) graphite nanoplatelets (GnPs) and hexagonal boron nitride (hBN) as ternary hybrid nanofillers. In the present study, the objective is focused on the synthesis of ternary hybrid nanofillers composed of CNT, GnP and hBN in different weight ratios, followed by the fabrication of Al-based hybrid nanocomposites reinforced with the various CNT-GnP-hBN ternary hybrid nanofillers using powder metallurgy technique. Leveraging the synergistic effects of these various nanofillers, the aim was to improve the mechanical and tribological properties of the Al-based hybrid nanocomposites. The Al matrix was reinforced with 1 wt.% of the various CNT-GnP-hBN ternary hybrid nanofillers, each comprising varying proportions in weight fractions of the individual nanofillers. The various ternary hybrid nanocomposites having compositions CNT0.45GnP0.45hBN0.1, CNT0.4GnP0.4hBN0.2, CNT0.2GnP0.2hBN0.6 and CNT0.1GnP0.1hBN0.8 were synthesized by ultrasonciating the individual nanofillers in proper weight fraction in acetone medium. The fabrication process of the various nanocomposites was done using both the conventional sintering and spark plasma sintering (SPS) techniques, ensuring comparative analysis. Microstructural and mechanical characterizations were conducted to evaluate the properties and performance of the developed nanocomposites. The incorporation of the CNT-GnP-hBN ternary hybrid nanofiller into the Al matrix revealed a significant enhancement in wear performance compared to the pure Al sample developed under similar conditions. However, it was observed that as the hBN content increased the nanocomposites exhibited a decrease in both relative density and hardness. Among SPSed nanocomposites, Al-1 wt.% CNT0.4GnP0.4hBN0.2 exhibited the maximum wear resistance, the highest hardness of ~ 716.33 MPa and the highest relative density of ~ 91.11%. The findings have practical implications for advancing lightweight, high-strength materials with enhanced wear resistance, making them suitable for various industrial applications.