Development of Al-Based Nanocomposites Using CNT-GnP-hBN Ternary Hybrid Reinforcement

Aluminium (Al) has low strength, limiting its applicability for certain technical applications seeking higher mechanical strength and deformation resistance. Integration of ternary hybrid reinforcement in Al offers a compelling opportunity to achieve a synergistic combination of multiple desirable properties opening new avenues for advanced engineering applications beyond what can be achieved with mono or binary reinforcement systems. Here, Al-based nanocomposites were developed by incorporating a ternary hybrid reinforcement system, consisting of graphite nanoplatelets (GnP), hBN and MWCNT. Al-1 wt.% GnP_0.3CNT_0.3hBN_0.4, Al-2 wt.% GnP_0.3CNT_0.3hBN_1.4, Al-3 wt.% GnP_0.3CNT_0.3hBN_2.4, and Al-5 wt.% GnP_0.3CNT_0.3hBN_4.4 nanocomposites were developed by powder metallurgy (PM) route. The results indicate that the Al-1 wt.% GnP_0.3MWCNT_0.3hBN_0.4 hybrid nanocomposite exhibits the highest wear resistance. Among the hBN-based nanocomposites, Al-3 wt.% hBN nanocomposite exhibited the best wear properties. Increasing the hBN loading level in the CNT-GnP-hBN ternary nanofiller system beyond 0.4 wt.% resulted in a deterioration of physical, mechanical and wear properties. Al-1 wt.% CNT_0.3GnP_0.3hBN_0.4 hybrid nanocomposite had the highest relative density and hardness of ∼92.56% of ∼415.91 MPa respectively. The compressive strength (σ_max) of Al-1 wt.% CNT_0.3GnP_0.3hBN_0.4 hybrid nanocomposite was ∼874.77 MPa, while the σ_max rapidly declined in the nanocomposites with the increased content of the CNT-GnP-hBN hybrid nanofiller.

Keywords:
Al-based nanocomposites; powder metallurgy (PM); hexagonal boron nitride (hBN); graphite nanoplatelets (GnP); multiwalled carbon nanotubes (MWCNT); hardness; wear