Towards closed-loop aerospace waste recycling: FAST nickel superalloy tooling for direct titanium waste-to-wire continuous extrusion

With increasing interest in wire additive technologies for titanium parts, there is increasing demand for low-cost wire from secondary sources, of which there is an abundance. In this investigation, both machining swarf and out-of-specification AM commercially pure titanium alloy powder have been successfully consolidated into wire using the solid-state CONFORM™ continuous extrusion process. Such wire from secondary sources has been directly compared with solid bar feedstock. Historically, one of the key challenges was the wear of CONFORM™ tooling. In this study, nickel superalloy waste powder was fully consolidated through the field-assisted sintering technology (FAST) to create novel recycled tooling. This study demonstrates the effect of the continuous extrusion process directly on each feed material and how the use of multiple sources of secondary aerospace waste can allow such a process to operate within a closed-loop recycling system. Machining swarf has been demonstrated to be a viable feedstock for wire production via the CONFORM™ process coupled with the use of recycled nickel superalloy tooling. Such metal circularity technology is timely as titanium- and nickel-based superalloy aerospace waste is predicted to increase over the next two decades to meet future aircraft build demands.