Synergistic Effects of Graphene and Ceria Nanoparticulates on Microstructure and Mechanical Behavior of Stir-Cast Hybrid Aluminum Composite

The current study deals with mechanical and microstructural analyses of Al6061/GNPs/CeO₂ hybrid composites. Hybrid aluminum metal matrix composites (HAMMCs) were manufactured using the 2-step stir-casting method, with the addition of GNPs and CeO₂ at varying weight percentage ratios (1:3, 3:3, and 3:1). The highest tensile strength, flexural strength, and impact strength were 113.666 MPa, 73.08 MPa, and 13.062 J, respectively. The hardness increased by 21.47 percent with a reduced particle grain size of 6.36 nm. The FESEM study verified fine grain refinement and homogeneous reinforcement distribution, whereas surface fractography of the tensile specimens determined the failure caused by the formation of cracks, pores, debonding, and large-sized dimples in the stir-cast alloy and HAMMCs.