Fracture Toughness of CF-Plug Joints of Ti and Epoxy Matrix CFRP

Abstract

A new method of linear connected joints (Ti/CF-plug/Epoxy) of Ti (Titanium) to Epoxy connected by CF-plug was innovated and developed, since fine carbon fibers (CFs) generate the extremely large friction force by their broad interface between metals and Epoxy polymer (M/Epoxy). Compared with glue and spontaneous adhesions of M/Glue/Epoxy and M/Epoxy, the new method remarkably improved the fracture toughness with maintaining light weight. To maintain the high joint strength of the Ti/CFW-CFJ/Epoxy, the Ni coating film on CF should control to bite the CF by molten Ti. The tensile strength (σb) and its strain (εb) of Ti/NiCFW-CFJ/Epoxy were higher than those of Ti/CFW-CFJ/Epoxy. In addition, increasing the CF-volume increases the σb. The CF-plug joint between Ti and Epoxy matrix CFRP apparently probably enhances the fuel efficiency, as well as safety level of airplane.