Microstructures and mechanical properties of Al nanocomposites hybrid-reinforced with B4C, carbon nanotubes and graphene nanoplatelets

Abstract

To improve the mechanical properties of Al-30%B4C composites, modified carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were added. The Al/B4C composites with different content of CNTs and GNPs were fabricated via ball milling and hot press. The B4C particles were homogeneously distributed, and the B4C/Al interface was tightly bonded due to AlB2 and Al3BC. With increase of CNTs content, the composites strength increased. The compressive strength of the Al-30%B4C-0.75%CNT-0.25%GNP composite was enhanced by 46% compared with that of the Al-30%B4C composite. The interface bonding and strengthening mechanisms of CNT-GNP hybrid were studied in detail. The reinforcements mainly reinforced the nanocomposites by Orowan, dislocation, grain refinement strengthening and load transfer. After calculation, CNT-GNP hybrid has lower contribution in thermal mismatch and Orowan strengthening due to the larger size. The load transfer efficiency of the CNT-GNP hybrid was significantly higher than that of the CNTs and GNPs, as the optimised interface structure and interconnected structure of the hybrids contributed to its high strength. © 2023 Elsevier B.V.