Friction Stir Blind Riveting for Dissimilar Materials

This award supports fundamental research on a novel one-sided joining process of dissimilar materials through friction stir blind riveting. The research objective is to establish the link among the thermomechanical inputs, material properties, microstructural characteristics, and resulting joint strength. Specifically, the research will formulate a physics-based thermo-mechanical model for intrinsic forces and torques with frictionally rotated rivet and validate the model experimentally; test the hypothesis that viscoplastic type material response can simulate metal deformation in friction stir blind riveting; investigate the effects of process conditions on material flow, defect formation, and joint strength; analyze microstructure evolution and its impacts on joint failure mechanisms; identify different thermomechanically affected zones; and assess the friction stir mechanisms for different joining materials.

Research results will provide knowledge and understanding to meet the critical need for the incorporation of advanced lightweight materials in the automotive industry. The capability to incorporate these lightweight materials in an automobile is crucial for improving fuel economy and reducing environmental impact. This technology combines the benefits of friction stir welding with the strength of blind rivets. The research will advance this new joining technique for a wide range of dissimilar materials, from metals to composites. Research findings will also have a broad impact on other transportation industries, such as aerospace, rail, and shipbuilding, where joining materials with different weights or functionalities is increasingly demanded but limited by traditional joining techniques. This project will promote active learning for industrial practitioners, and broaden participation of underrepresented student groups. The research outcomes will be integrated into undergraduate/graduate course development, and hands-on modules for K12 education.