With the unique class, the reinforcements play a precious role during the composite fabrication, expanding the specific properties. The novel research intensively enhances the micro-structural and mechanical behaviour of magnesium alloy (AZ63/3 wt% boron nitride) nanocomposite featured 2, 4, and 6 wt% of nano-size silicon carbide (SiC) particles via liquid state vacuum stir cast route. The exposure of SiC and BN on composite density, voids contribution, changes in AZ91D microstructure, impact toughness, hardness, and stress-strain individuality of AZ63 alloy nanocomposite is evaluated with ASTM policy. The composite composed with 3 wt% BN and 6 wt% SiC proved their identity. It showed the lower contribution of voids-free homogenous dispersion particle results in a maximum impact strength of 14.7J/mm2, hardness of 74HV, and superb tensile strength of 247MPa. This optimum behaviour will be recommended for automotive roof frame applications. © 2024 Informa UK Limited, trading as Taylor & Francis Group.