Exploring the Impact of Pure Copper Powder Reuse on Surface Chemistry During Powder Bed Fusion-Electron Beam

Abstract

The degradation of powder feedstock during additive manufacturing (AM) processes can significantly impact part quality, material utilization, and overall process sustainability. Pure copper, a material with high optical reflectivity, excellent thermal and electrical conductivity, is a promising candidate for powder bed fusion–electron beam (PBF-EB) manufacturing due to the process's ability to melt materials regardless of reflectivity under a controlled vacuum environment that prevents oxidation. This study examines the effects of pure copper powder properties and powder reuse on surface oxide chemistry and subsequent processability in PBF-EB. High-resolution scanning electron microscopy (HR-SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze changes in powder surface chemistry before and after reuse. The results demonstrate changes in surface chemistry with an elevated oxygen content, a thicker surface oxide layer, and the transformation of CuO to Cu2O, as well as the formation of Cu (OH)2 on the powder surface during handling. These changes can adversely affect the AM process, potentially leading to defects, reduced part quality, and decreased material utilization.