This Grant Opportunity for Academic Liason with Industry (GOALI) award supports the study of a new forming process to create a mechanical joint between dissimilar materials. Friction stir forming will be studied by experimental, modeling, and material analyses. The intrinsic process forces and temperature will be measured. The effect of process parameters on the material deformation and joint strength will be experimentally investigated. A more accurate modeling prediction of thermo-mechanical material behavior will be made. A complete metallurgical analysis will be conducted to characterize the effect of friction stir forming on the work material grain structure. This new, efficient process has a relatively small environmental footprint and will be capable of simultaneously heating and forming the work material into a strong dissimilar material joint.
If successful, this new joining process will result in a stronger, lighter joint made entirely from the parent material in a variety of dissimilar materials. The process is a quick one-step process without the need for external fasteners, fluids, or any other material. In traditional joining methods, such as fusion processes, joint strength in dissimilar metal joints is limited. The major goal of this research is to establish the link among the force/heat input, material structure, material properties, and resulting joint strength. The nature of work material forming at high temperature will be fully characterized and the proposed work will contribute extensive knowledge about material forming by friction stir processes. This research will stimulate new avenues and applications for friction stir processes, and make them suitable for a wide range of materials. General Motors is a partner in the research and will implement the process into the manufacture of their automotive body structures.