Investigation of the hybridization effect of cost-effectively compounded pre-impregnated glass fabric on sheet molding compound

Hybridized sheet molding compound (hybrid SMC) with pre-impregnated glass fiber fabric (F-SMC) was identified as a promising solution for applying on the subcomponents of the battery casing based on numerical structural analysis. A lower part weight and cost with fewer assembly processes than the state-of-the-art technology made of aluminum were shown. To further evaluate the manufacturing feasibility of co-molding F-SMC with basic SMC and the resulting hybridization effect on the mechanical properties, the study below has been conducted. The manufacturing feasibility was investigated at an 1800-ton hydraulic press at AZL. Two different F-SMCs with varied weft and warp ratios and different laminate architectures (sandwich structure and one-sided) were considered on a 3D tray-based part, similar to a battery tray. For the variant, F-SMC on one side, it is easy to be over-molded by the basic SMC using the standard compression process parameters. For the sandwich structure, the cavity between the F-SMCs can also be filled. Both layouts present an excellent interface without any significant air voids investigated by optical microscopy. In addition, the mechanical properties were studied under the uniaxial transverse loading on one homemade test cell. Compared with the F-SMC on one side under compression stress, the sandwich structures provide a much more significant reinforcing effect with an average increase in the flexural modulus, flexural strength, and absorbed energy at target deformation by 61.3 %, 78.2 %, and 88.4 %, respectively. The failure modes were microscopically investigated and determined. After the lifetime, the components can be easily recycled with the hybrid SMC’s consistent resin and fiber type.