Research on Joint Strength and Mechanism of Composite/Aluminum Alloy Connections Based on FDS Technology

This paper applies Flow Drill Screws (FDS) technology to the joining of composite materials and metal materials. It investigates the connection strength and mechanism between thermosetting carbon fiber reinforced composites and metal materials, as well as between thermoplastic carbon fiber reinforced composites and metal materials. The study includes shear tests and metallographic tests to analyze the two types of connections. The experimental results demonstrate the feasibility of using the FDS process for composite materials and metal materials. It is found that the FDS process is more suitable for connecting thermoplastic composites and metal materials compared to thermosetting composites and metal. This type of connection exhibits a smaller damage range at the interface and allows the thermoplastic matrix to effectively fill the threaded connection area after heating. Additionally, the micro-mechanical interlocks generated at the laminate interface can effectively increase the connection strength.