The crucial role of friction bit joining in advanced lightweight design: a review

In recent years, the automotive industry has accelerated the development of high-strength and low-weight designs by employing dissimilar combinations of materials to generate a lighter overall weight and fuel efficiency. Unfortunately, conventional welding techniques generally face compatibility issues with these combinations of materials, e.g. steel and aluminium alloys, due to the formation of brittle intermetallic compounds, among other deficiencies. In this review, the authors provide a complete review of Friction Bit Joining (FBJ) as a solid-state joining technique that can influence conventional welding methods; the review gives a critical evaluation of the most recent developments in the FBJ process with regard to joining dissimilar metallic materials within the automotive industry. In summary, the review identifies the changes to the mechanical properties and advantageous microstructural features as compared to the base metals that are produced through the FBJ process. The review also provides a comprehensive synthesis of the range of published data on FBJ to demonstrate why FBJ meets the requirements for a robust, quality joining process suitable for the modern vehicles.