Characterization, preparation, and reuse of metallic powders for laser powder bed fusion: A review

Abstract Laser powder bed fusion (L-PBF) has attracted significant attention since its inception, providing unprecedented advantages to fabricate metallic components with complex geometry. The quality and performance of as-printed alloys is an intricate function consisting of numerous factors linking the feedstock powders, manufacturing, and post-treatment. As the starting materials, powders play a critical role in influencing the printing consistency, total fabrication cost, and mechanical properties. In consideration of its importance for L-PBF, the present review aims to review the recent progress on metallic powders for L-PBF focusing on powder characterization, powder fabrication, and powder reuse. The methods of powder characterization and fabrication were presented in the beginning by analyzing the principles and corresponding advantages and limitations. Subsequently, the effect of powder reuse on the powder characteristics and mechanical performance of L-PBF parts is analyzed focusing on steels, nickel-based superalloys, Ti and Ti alloys, and Al alloys. The evolution trend of powders and as-printed parts varies for different alloy systems based on the existing studies, which makes the proposal of a unified reuse protocol infeasible. Finally, perspectives are presented to cater to the increasing applications of AM technologies for future investigations. The present state-of-the-art work can pave the way for the broad industrial applications of L-PBF by enhancing printing consistency and reducing the total cost from the perspective of powders.