Effect of powder reuse on CoCrMo alloy feedstock and printed parts in laser powder bed fusion

In laser powder bed fusion (LPBF) of metallic materials, the cost of feedstock powder is a major contributor to overall manufacturing expenses. Therefore, enhancing the economic sustainability of the LPBF process requires effective powder reuse strategies, particularly for high‑performance alloys. In this work, Co‑28Cr‑6Mo powder was reused 17 times, without refreshing using virgin powder (i.e., “continuous reuse”), under industrial production environment to fabricate both solid and porous coupons. Comprehensive characterization was performed on both the reused powders and the fabricated coupons to evaluate changes in morphology, particle size distribution, and chemical composition of powder, as well as the density and tensile properties of solid coupons and the gravimetric porosity, compressive yield strength, and tensile attachment strength of porous coupons. The chemical compositions of both the reused powders and the printed coupons remained within the limits specified by ASTM F3213 , even after 17 reuse cycles, with no significant compositional changes. Overall, the powders exhibited a slight increase in particle size as reuse progressed. The relative density of the solid coupons remained steady, ranging from 99.76% to 100% across all reuse cycles. A slight enhancement in tensile properties was detected in coupons produced using reused powder; however, the magnitude of this change was not considered practically meaningful. Similarly, the compressive yield and tensile attachment strengths of porous coupons showed no significant changes as a function of powder reuse cycles. Despite minor variations in powder chemistry and particle size, the mechanical and physical properties of both solid and porous coupons remained very stable, with no evidence of degradation observed up to 17 times of continuous reuse (i.e., 18 build cycles).