The research objective of this Collaborative Research Grant Opportunity for Academic Liaison with Industry (GOALI) award is to advance the fundamental understanding of electron beam manufacturing through broad-based modeling tied to process development. The approach involves the development of simulation-based process maps for three key deposit features: melt pool size, residual stress and microstructure. Process maps will be developed using thermomechanical numerical models guided by mechanics and materials insight into governing nondimensional thermal and mechanical process variables. Results from large numbers of numerical simulations of electron beam processes will be presented as quasi-nondimensional plots (process maps) valid for deposition of a single alloy over the full practical range of process variables. These plots will allow the prediction of melt pool size, residual stress and microstructure as a function of process variables such as beam power, beam velocity, part preheat temperature and part size. In addition, this approach will be used to consider processing scenarios unique to electron beam manufacturing, such as the tailoring of melt pool shape using rapid movement of the electron beam within the melt pool.
If successful, the results of this research will provide a fundamental understanding of how electron beam process variables relate to final part quality. This will provide a much needed basis for comparing the relative strengths of electron beam and competing laser-based processes in the fabrication and repair of a wide range of practical components. Students working on this project will develop a multidisciplinary background in manufacturing, solid mechanics, heat transfer and materials that will make them highly valuable in both industry and academia. Finally, project activities will be integrated with ongoing NSF-supported engineering education initiatives at both academic institutions.
