Study of microstructure and mechanical behaviour of aluminium alloy hybrid composite with boron carbide and graphene nanoplatelets

Lightweight materials with superior designs and improved properties have always been in demand of the aerospace and automobile industries for improved performance. Spark plasma sintering was employed in the present study for the fabrication of a hybrid composite of boron carbide and graphene nanoplatelets. Reference samples and composites with 0.1 wt% GNPs, 1 wt% B4C and hybrid combination containing 0.1 wt% GNPs and 1 wt% B4C in Al6061 matrix were prepared. All the samples were divided into two groups, namely; as fabricated and artificially age hardened (T6). Electron backscattered diffraction technique was employed to evaluate the microstructure along with the optical and scanning electron microscopy. Various illustrative models have been conceived to describe the physical behaviours of the composites. Improvements in hardness (33% & 50%) and tensile strength (11% & 20%) were exhibited by the hybrid composite in F and T6 conditions, respectively. The strengthening mechanism is explained with the help of fractography. The fractured surfaces revealed uniform distribution of reinforcements and extensive crack deflection.