FMRG: Eco: Manufacturing USA: Multi-Nozzle Metal Jet Additive Manufacturing with Recycled Feedstock Materials

Additive manufacturing, often referred to as three-dimensional (3D) printing, fabricates components by selectively printing one layer of material on top of another to form a three-dimensional (3D) shape. Industrial grade additive manufacturing machines used in the aerospace and defense industries produce high performance structural metal parts. However, high costs and relatively low production speeds have greatly limited industrial use of these technologies beyond a few aerospace applications.

This Future Manufacturing grant seeks to expand industrial adoption of metal additive manufacturing using an efficient molten metal droplet jetting process that is akin to high-speed inkjet printing using molten metal as the "ink". Process knowledge generated via this research helps make domestic manufacturing of metal components competitive with overseas competition in terms of both cost and speed.

Three hallmarks of the process are that it intended to process both new and recycled metal as the feedstock material, there is very little scrap produced, and labor costs are minimal. This improves the business case for reshoring domestic manufacturing by lowering the costs per part. The ability to convert scrap metal such as machining chips into new parts is particularly important for commercial and military supply chain scenarios where resources are scarce.

The project looks to advance education and workforce development through summer camps and certificate courses in additive manufacturing.

The ambitious goal for this Future Manufacturing research is to enable additive manufacturing of metal components that are competitive with traditional casting and machining processes on the bases of cost, speed, and quality. The technology used is a novel multi-nozzle molten metal jetting process. Unlike most metal additive processes, this process melts metal prior to deposition rather than during deposition.

This allows any form of metal feedstock material to be used, including ingot, rod, wire, and recycled material. Several scientific contributions are needed to realize the ambitious goals of the project. High material deposition rates are needed for this process to be competitive with traditional processes.

Multi-physics modeling are used to determine the conditions under which progressively higher frequency jetting of molten metal droplets is possible. Throughput is also increased using multi-nozzle arrays. Computationally efficient thermal modeling techniques are employed to better understand the relationship between multi-nozzle jetting strategies and part quality as determined by evaluation of microstructure and porosity.

Lastly, the quality of material produced from recycled metal feedstock is compared with that of virgin material, and lifecycle analysis tools are used to quantify the relative impacts associated with different recycled material usage scenarios.

This Future Manufacturing award is co-funded by the Division of Materials Research (DMR) in the Directorate for Mathematical and Physical Sciences (MPS) and Divisions of CMMI, CBET and ECCS in the ENG Directorate.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.