Additive Preform Molding of continuous carbon fiber thermoset composites

Abstract

Continuous carbon fiber thermoset composites are renowned for their exceptional mechanical and thermal properties. However, fabricating complex 3D composites has historically presented challenges due to their structural complexity. This study presents the Additive Preform Molding (APM) strategy, a novel hybrid manufacturing method that integrates additive manufacturing with overmolding to produce high-performance composite structures. APM optimizes the alignment of continuous fibers based on load requirements and enhances structural integrity, starting with the creation of semi-cured preforms. These preforms are precisely shaped into specific configurations and subsequently overmolded with an infusion of short fiber-reinforced epoxy, thus enhancing their mechanical properties and facilitating the design of intricate geometries. The versatility of APM is represented through fabrication of various bracket designs. Mechanical testing reveals a tensile strength of 1109.3 MPa, a tensile modulus of 103.5 GPa, a flexural strength of 854.7 MPa and a flexural modulus of 96.6 GPa, confirming its substantial load-bearing capabilities for high-performance applications. This study demonstrates that APM is not only a viable alternative to traditional composite manufacturing methods but also an ideal solution for producing complex, high-strength 3D composite structures.