Publications

Microstructural Modification and Healing of Additively Manufactured Parts by Electropulsing

Noell, Philip N.; Rodelas, Jeffrey R.; Ghanbari, Zahra G.; Laursen, Christopher M.

For many applications, the promises of additive manufacturing (AM) of rapid development cycles and fabrication of ready-to-use, geometrically-complex parts cannot be realized because of cumbersome thermal postprocessing. This postprocessing is necessary when the non- equilibrium microstructures produced by AM lead to poor material properties. This study investigated if electropulsing, the process of sending high-current-density electrical pulses through a metallic part, could be used to modify the material properties of AM parts. This process has been used to modify conventional wrought materials but has never been applied to AM materials. Two representative AM materials were examined: 316L stainless steel and A1Si10Mg. Two hours of annealing are needed to remove chemical microsegregation in AM 316L; using electropulsing, this was accomplished in 200 seconds. The ductility of AlSil0Mg parts was increased above that of the as-built material using electropulsing. This study demonstrated that electropulsing can be used to modify the microstructures of AM metals. ACKNOWLEDGEMENTS The authors would like to acknowledge Jay Carroll for beneficial discussions and supplying material. Also, the authors would like to acknowledge Zachary Casias, Peter Duran, John Laing, Sara Dickens, Celedonio Jaramillo, Renae Hickman, and Christina Profazi for their exceptional experimental support.