Influence of characteristic eutectic free microstructure on mechanical and corrosion response of spark plasma sintered hypereutectic Al-Si alloy

•Hypereutectic Al-Si processed through spark plasma sintering (SPS) and cast route.•Interfacial eutectic melting in SPS produces microstructure different from cast.•Finer eutectic Si in SPSed microstructure substantially enhances the failure strain.•SPSed microstructure prevents anodic dissolution and improves corrosion resistance. Spark plasma sintered hypereutectic Al-Si alloy, free from characteristic eutectic microstructure was evaluated for its mechanical and corrosion behaviour in comparison with conventional cast microstructure having coarser primary Si and acicular eutectic Si. In SPSed microstructure, Al region free from acicular eutectic imparts substantial failure strain under compression loading. Absence of coarser primary Si and acicular eutectic Si in SPSed microstructure prevents the rate of anodic dissolution, specifically at the Al-Si interface and enhances corrosion resistance than the cast microstructure in 3.5 wt% NaCl corrosive medium.