Influence of Al₂O₃ and B₄C Hybrid Reinforcements on the Mechanical Properties and WEDM Machinability of Aluminum Matrix Composites

The Mechanical Properties and WEDM performance of AMCs containing Al₂O₃ and B₄C are investigated in this study. A total of nine composite specimens were prepared by the stir-casting method with different weight percentages of Al₂O₃ and B₄C reinforcements. The Microstructural, Tensile Strength, Hardness, Wear Behavior, and WEDM responses, such as MRR, Surface Roughness (SR), and kerf width of the prepared composites, were investigated. Of all combinations investigated, the hybrid composition with 5% Al₂O₃ and 3% B₄C displayed indeed maximum mechanical properties along with better machinability (higher MRR as well as lower Ra). Microstructural studies through X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) indicated a homogeneous distribution of reinforcing particles with few pores, resulting in better performance. The synergistic effect of the reinforcement exhibited a synergetic interaction -that is, Al₂O₃ provided improved hardness and heat stability, whereas B₄C enhanced the lubrication property and wear resistance. The optimization process using Taguchi’s L27 orthogonal array and ANOVA analysis also indicates the important parameters and potential influence of reinforcement composition and WEDM on the response. The results in general suggest that Al– Al₂O₃/B₄C hybrid composites have a good potential for the aerospace and automotive industry, requiring high strength along with efficient EDM machinability.