Carbon Fiber-reinforced Plastic Surface Modification by Al Electroplating in AlCl<sub>3</sub>–EmImCl Ionic Liquids

In this study, Al electroplating and anodization were performed to improve the wear resistance of the carbon fiber-reinforced plastic (CFRP) surface. The adhesion strength between the Al electroplating film and CFRP was improved by etching the resin part of the CFRP surface using a sulfuric acid treatment to increase the area occupied by the conductive carbon fibers. The surface roughness of CFRP increased with increasing etching time, resulting in CFRP surfaces with roughness of up to 8 µm. The adhesion strength between those etched surfaces and the Al-electroplated film increased with increasing etching time, and an anodized layer was formed on the CFRP substrate by anodizing the Al-electroplated film. The Vickers hardness of the anodizing layer was 318 Hv, which was approximately seven times higher than that of the CFRP substrate, i.e., 44 Hv.