Effect of fabrication techniques on mechanical and microstructural behavior of AA7075/SiC/ZrC hybrid composite

Abstract

Aluminum composites are highly sought-after in the industrial sector due to their improved mechanical properties compared to their parent metals. The choice of fabrication technique has a significant impact on the mechanical behavior of the composite. This study investigated the mechanical behavior of an optimized weight-fractioned AA7075/SiC/ZrC hybrid composite using different fabrication techniques. Stir casting, conventional sintering, and microwave sintering methods were employed to produce the composites. By optimizing the ball milling parameters, a uniform distribution of reinforcement particles was achieved throughout the matrix material. XRD, porosity, microstructural, and mechanical tests were conducted on all three composites to analyze the major changes during fabrication. Remarkably, the composites fabricated through microwave sintering exhibited significantly higher strength than the other fabrication methods. Specifically, the microwave-sintered composites displayed a compressive strength of 389 MPa, a tensile strength of 321 MPa, and a strain-to-fracture value of 26%. In contrast, the stir-cast composites showed a larger scale of secondary phases, poor mechanical performance, and elevated porosity. Moreover, when considering the overall production cost associated with the different fabrication techniques investigated in this study, microwave sintering was the most cost-effective method for large-scale production. This suggests that microwave sintering offers superior mechanical properties and economic advantages regarding manufacturing expenses.