Bioaccessibility and reactivity of alloy powders used in powder bed fusion additive manufacturing

Exposure to metal particles via the inhalation route unavoidably takes place at occupational settings during additive manufacturing of metals and alloys. This calls for investigations on possible adverse health effects. study focuses virgin reused powders three iron- nickel-based alloy (316L, IN718, 18Ni300) widely used in manufacturing, dust powder 18Ni300 generated laser melting. Investigations were performed from a physico-chemical toxicological perspective assessing their bioaccessibility artificial lysosomal fluid (ALF, simulating lung exposure respirable particles), corrosion behavior, surface morphology composition, microstructure, hydrodynamic size distribution ALF, in-vitro toxicity towards cultured human cells. Less than 1% mass was dissolved passive alloys IN718) under simulated physiological conditions (pH4.5, 37 °C, 24 h), whereas iron-nickel showed an active behavior completely. Reused IN718 no, or only minor, differences oxide release pattern, compared with powders. After reuse, 316L enrichment manganese within outermost surface, increased current, amounts released iron fraction ferritic which extent particle aggregation. All low, negligible, cytotoxic potency reactive oxygen species formation. Powder bed fusion using melting can hence affect chemical, physical, properties non-fused powders, which, if reused, could influence printed part.