With the development of technology, industries have observed that hybrid materials (composites) are a promising solution due to the combination of their distinct mechanical properties. However, one of the major challenges to be mastered is the manufacturing process and the bonding interface between the materials. Numerical simulation analyses have been widely applied and studied as basic tools for predicting the behavior of hybrid composite materials. However, for simulation to be effective, a broad understanding of the mechanical properties of the material under study is first required. To assess the potential for improvement in the materials’ characteristics, a total of 15 test specimens were developed in the form of sandwich panels, composed of two layers of 334HM carbon fiber impregnated with epoxy resin and a core made of 6063-T6 aluminum. The core material was prepared with three distinct surfaces: five natural tests, five sanded tests with No. 60 sandpaper, and five blasted tests with microspheres. This test was performed to predict potential improvements in adhesion between the core and the composite. After lamination, the specimens were subjected to three-point flexural testing using a universal testing machine. By applying different forces and loads, the material responses and their ability to withstand stresses and deformations were evaluated, as well as the adhesion characteristics between the composite and the hybrid core. This process provided essential data for calculating the material’s ultimate loads, including bending stress, elastic modulus, tensile stress, and yield strength. After comparing the results of the different surfaces, it was concluded that the preparation of the sandblasted aluminum surface had a superior performance to the others, given that its roughness allows for better adhesion of the resin/fiber to the material. In addition, it also presented the best mechanical behavior, providing an improvement of approximately 44.40% in its characteristics compared to pure 6063-T6 aluminum.