Metal Digital Direct Manufacturing (MDDM) for Close-Out of Combustion Chambers and Nozzle Fabrications

Use of additive manufacturing (AM) techniques are of interest as they can be used to create complex shaped rocket components in addition to the potential for multi-material, or functionally graded materials (FGM). The main technical challenge lies in the ability to deposit various materials at relatively large diameters with the desired properties while maintaining the overall structural integrity of the assembly. Use of interface materials can also assist in joining these very dissimilar metals ranging from Cu-based to Ni-based alloys. In response to this need, Keystone, in collaboration with MSU, is proposing a Phase 1 STTR project to demonstrate the feasibility of applying the Robotic Pulsed-Arc AM process to fabricate FGM Cu-to-Ni components in support of advanced engines for the Space Launch System (SLS) vehicle. During the Phase II the Keystone team envisions maturing the processes to AM a 21-inch diameter cooled nozzle for delivery to the NASA for machining and preparation for hot fire testing by the NASA.