An RSM modelling and optimization of mechanical behaviour of AlSi12CuNiMg-micro/nano B₄C composites through two-step stir-casting

Aluminium alloy hybrid composites are extensively utilized in sectors like aerospace, automotive, and packaging industries. This work investigates the effect of micro-nano B₄C reinforcement on the mechanical behaviour of AlSi12CuNiMg alloy composites. A modified stir-casting route was used to produce the AlSi12CuNiMg composites reinforced with micro and nano B₄C particles. Various proportions of micro-B₄C along with 0.5 wt.% of nano-B₄C were injected into the molten AlSi12CuNiMg alloy through dual step stir casting. An RSM model based on central composite design was applied to optimize the operating parameters for fabricating the AlSi12CuNiMg composites with better strength and hardness. The parameters considered for physical experiment in this study were melting temperature, stirring speed and micro B₄C reinforcement. The optimal fabrication conditions were melting temperature of 749.09 °C, stirring speed of 173.6 rpm, and micro B₄C reinforcement of 5.18 wt.%. Under this scenario, the AlSi12CuNiMg-B4C composite exhibited highest density of 97.28%, hardness of 89.87 HV and tensile strength of 170.84 MPa.