Porosity control of copper-based alloys via powder bed fusion additive manufacturing for spacecraft applications

Tunable copper porous architectures are of interest in spacecraft applications requiring tailored electrical, thermal, and catalytic properties. Additive manufacturing techniques have demonstrated great promise for generating architectured structures, however, the fabrication of porous metal components is commonly limited by process-defined resolutions which practically limits porous features to the 100 μm range. A novel alternative technique to generate sub-millimeter-scale porosity in powder bed fusion additive manufacturing is to utilize parameter-induced porosity. Although this technique has been demonstrated for iron, aluminum, titanium, and nickel-based alloys, copper-based alloys are yet to be explored. To establish the requisite relationship between powder bed fusion parameters, resultant porosity and material properties, the processing of copper, bronze, and brass samples was explored. Control of porosity was demonstrated with porosity bands of 23.5–47.9% for copper, 0.8–55.3% for bronze, and 8.0–50.2% for brass. Additional electrical and mechanical characterization highlighted the influence of parameter selection and subsequent porosity on bulk material properties.