SBIR Phase I: Joining of Dissimilar Materials Using Rivet-Weld Technology

This Small Business Innovation Research (SBIR) Phase I project will establish the technical feasibility and demonstrate the commercial potential of a new rivet-weld technology for joining dissimilar materials in manufacturing light weight vehicle structures for sustainable transportation. Reducing vehicle weight has been a primary goal of the automotive and aircraft manufacturers in order to improve fuel efficiency and reduce pollution. An effective approach to weight reduction is to create optimized multi-material structures by tailoring different materials to the specific areas of a structure according to their properties. The challenge in producing such multi-material structures lies in materials joining since traditional welding techniques cannot be applied to joining such dissimilar materials due to limitations of weldability. A hybrid technology that combines the advantages of self-piercing riveting and resistance spot welding was invented. The intellectual merits of the project are (1) a new joining technology to enable the joining of aluminum to high strength steels and the creation of innovation joint configurations such as sheet to tube joining, (2) computational method for optimizing the rivet designs tailored for the specific material and joint configurations, and (3) algorithms for controlling the rivet-weld process. The broader impact/commercial potential of this project is to enable design and construction of light weight structures such as automotive bodies. It has been established that every 10% reduction in vehicle weight will result in an improvement in fuel efficiency between 6~8%. With the increasing interest in full electric and hybrid electric vehicles, reduced vehicle weight will translate to smaller batteries and longer driving range for each charge. All these will lead to reduced energy consumptions and emissions. In addition, the rivet-weld technology will allow manufacturers to produce multi-material structure using existing assembly plant infrastructure. The rivet weld machines can be adopted onto welding robots or stationary machines on the assembly lines with minimum reconfiguration.