In lab, AI finds 500 W DED settings for NASA alloy

On a five-axis powder-fed Directed Energy Deposition system, researchers at Washington State University and the University of Minnesota found a workable route to print NASA’s GRCop-42 copper alloy at 500 W laser power. Their artificial intelligence (AI)-guided method, called BEAM, reached that lowest tested level after 37 failed experiments conducted over several months. The parts are laboratory demonstrations, not aerospace-qualified hardware.

DED is a metal 3D-printing process that uses a laser and a feed of metal powder to build a part. GRCop-42 is a copper-chromium-niobium alloy NASA developed for high-temperature aerospace applications. Its thermal conductivity and elevated-temperature properties suit components exposed to high heat flux, but copper absorbs relatively little infrared radiation from conventional fiber lasers and rapidly dissipates heat from the processing region. The team describes establishing a process window below 900 W as particularly difficult.

BEAM narrows that search by learning from previous successful and failed prints, selecting promising parameter combinations, and updating its model after each physical test. Unlike conventional Bayesian optimization, which typically searches for an optimum, BEAM looks for multiple feasible configurations and uses domain knowledge to exclude unrealistic combinations. In this study, it tested fixed laser powers of 950 W, 700 W, 600 W and 500 W, with an initial budget of ten experiments at each level.

The successful settings pointed to a process insight: they generally paired high scan speeds with low layer heights. One viable 700 W configuration used a 1600 mm/min scan speed and a 0.11 mm layer height. At 500 W, the successful setup used a 250 mm/min scan speed and a 0.3 mm layer height. The researchers first demonstrated the settings on test blocks, then produced larger cylindrical specimens. After machining, a cylinder printed at 700 W showed a solid interior with minimal defects, while its cross-section showed an even transition between Inconel 718 and GRCop-42.

The practical consequence is a shorter, more targeted route for teams establishing metal additive-manufacturing parameters: the study focused on reducing the time and resources needed to identify workable conditions, and says the result could widen access to lower-power DED systems. The campaign lasted three months, but it did not qualify the parts for aerospace service. The researchers’ next step is to extend BEAM to additional alloys and compositions.