This project aims at creating a complete agile manufacturing process that enables the reuse of the most abundant metal waste, ferrous (iron) wastes, at forward operating bases (FOBs) to produce needed parts for the warfighter. The objectives of this project are:

1. To create an effective sorting, chemical composition monitoring and composition adjustment process for the ferrous (iron) wastes at FOBs that enables quality control of the material for subsequent rapid investment casting.
2. To establish additive manufacturing (AM) technology of stereo lithography apparatus（SLA) enabled investment casting (IC) using ferrous wastes from FOBs as the cast material.
3. To develop post process treatments for upgrading the quality of cast parts.

This project will carefully study the three stages that the proposed manufacturing process is composed of: the quality control of the feeding material, the SLA enabled IC process, and the post process treatments. The research team has extensive and complementary expertise in metal processing, heat treatment, materials modeling and simulation, characterization, additive manufacturing, inspection and quality control, and scrap metal separation and sorting.

A comprehensive scrap sorting and molten steel compositions control process will be created using magnetic separation, Laser Induced Breakdown Spectroscopy (LIBS), X-ray fluorescence (XRF), and modeling and simulation of steel composition to provide real time in situ monitoring and control to obtain desirable steel composition for IC.    

A QuickCast™ module of the ProJet® 6000 HD SLA machine will be employed to explore both fabrication of wax injection molds and the fabrication of sacrifice resin patterns for IC. Patterns with various complexities will be designed and printed. The influence of printing parameters, including layer thickness, scan strategy, and hatch spacing, on pattern property will be studied. Investment casting will be performed using the molten steel with desirable composition from ferrous wastes from FOBs. The tolerances and surface roughness of final cast parts made by SLA enabled IC will be examined by dimension measurements and confocal microscope measurement. Product inspection will be conducted by ultrasonic testing, eddy current testing, and computed tomography (CT) scan. The mechanical properties, chemical composition and microstructures of cast parts will be investigated by mechanical tests, x-ray diffraction, scanning electron microscopy, and Energy-dispersive X-ray spectroscopy (EDX). The process will be optimized.

Post-process heat treatment will also be studied to control the microstructure and mechanical properties of the cast product. Effective heat treatment processes will be identified and developed if necessary for various compositions. 

Success of this project will bring multi-fold benefits to the Department of Defense (DoD) such as: a) a reduction in the military’s logistics tail by reusing part of iron wastes; b) the proof of feasibility of a field-capable manufacturing process allowing the warfighter to potentially fabricate replacement parts or perform repair operations; c) reduction in equipment downtime by rapid manufacturing on-demand near the point of use; d) increase in operational readiness.