Abstract
Hybrid alumina (Al2O3) ceramic nanocomposites containing 3 wt% silicon carbide nanoparticles (SiCnp) and 0.5 wt% multilayer graphene (MLG) were consolidated to near theoretical density (99%) by an inductive hot-pressing (IHP) technology. The enhanced fracture toughness and hardness by 97% and 15% respectively, for the hybrid nanocomposites over the reference Al2O3 were attributed to the higher densification, uniformly dispersed reinforcing constituents within the base matrix, toughening mechanisms of crack-deflection by the 0D-SiCnp and grain-anchoring as well as crack-bridging induced by the 2D-MLG. Thermal investigations of the hybrid nanocomposite verified the occurrence of a chemical reaction at the MLG/Al2O3 interface and thermal diffusion at SiCnp/Al2O3 interface during inductive hot-pressing. The bonding characteristics and interfacial microstructure were appraised by infra-red spectroscopy and high-resolution TEM microscope. Furthermore, the thermal stability in different gaseous environments and the ballistic performance of the hybrid nanocomposites were characterized and discussed. The produced hybrid nanocomposites may be suitable for high-temperature aerospace structural parts and may have applications in high-velocity impact technology.
•Dense hybrid nanocomposites were prepared by inductive hot pressing method.•The hybrid nanocomposites demonstrated 97% higher fracture toughness over Al2O3.•Hybrid nanocomposites manifested high thermal stability and ballistic performance.•Reinforcing phases (SiC and MLG) formed sturdy interface with Al2O3 matrix.