Effect of Electrical Conditions on the Mechanical Properties of CFRP Fabricated by Electrodeposition Resin Molding

Abstract

Traditional composite manufacturing methods for carbon fiber-reinforced plastics (CFRPs), such as autoclave molding, are costly and unsuitable for mass production. Electrodeposition resin molding (EDRM), a cost-effective alternative, is a novel resin-impregnation method in which the resin is electrochemically deposited around the fibers without external pressure. This study investigated the effect of terminating conditions of the EDRM process on the bending modulus and strength of the resulting CFRP using resistance as an indicator of resin impregnation. Four-point bending tests demonstrated that the bending modulus and strength increased with resistance for values below 13,000 Ω. Specifically, specimens prepared at 12,000 Ω showed approximately 33％ higher bending strength than those prepared at 5,000 Ω, which can be attributed to reduced void content and improved fiber-resin bonding. At values above 13,000 Ω, the bending modulus showed no correlation, and the bending strength exhibited a weak negative correlation with the resistance. This is likely due to excess resin deposition, which lowers the volume fraction of the fiber. Thus, an optimal resistance threshold of approximately 13,000 Ω is required for maximizing the mechanical performance of CFRPs produced by EDRM.