Study on the Effects of Pre‐Curing and Compression Molding Techniques on the Forming Quality and Mechanical Properties of U‐Shaped Al/ CFRP Hybrid Laminate Parts

Carbon fiber reinforced polymer (CFRP) hybrid laminates with aluminum alloys have been shown to exhibit outstanding comprehensive properties, leading to their widespread use in aerospace and automotive manufacturing. However, during the forming process of U‐shaped parts, defects such as thickness deviations, voids, and interlaminar delamination are prone to occur. These defects severely limit improvements in part forming quality and mechanical properties. This study employed a systematic approach to examine how pre‐curing and compression molding techniques affect the quality and strength of these parts. The results show that partial resin crosslinking improves interfacial bonding, stabilizes resin flow and yields a more uniform thickness distribution. Compared with direct compression molding, this technique reduced the average thickness variation by 7.11%. It effectively reduces small defects, such as interlaminar delamination, fiber breakage, and voids. It also reduced the resin extrusion by 48.21%. The study found that the average porosity of the parts decreased to 1.71%, and the average shear angle decreased to 14.24°. The peak load of the parts reached 28,274 N, with an energy absorption of 438.48 J and specific energy absorption of 4.43 J/g. Compared with those of direct compression molding, these values increased by 9.33%, 33.95%, and 33.94%, respectively. This technique improved the quality and strength of U‐shaped parts made of Al/CFRP hybrid laminates. This study provides a scientific basis for improving the precision‐forming techniques for these parts.