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Powder contamination during laser powder bed fusion is a critical concern for the quality assurance of parts. Herein, we studied the effect of Inconel 718 contamination on the properties of printed Ti6Al4V, two commonly printed alloys. Contaminated parts exhibited visual and microstructural defects, and a mere 0.5wt% IN718 contamination resulted in a 43% reduction in plastic strain without noticing surface-level cracking. Further contamination of 2.5 wt% IN718 promotes surface cracking that renders the material unable to deform plastically, highlighting the importance of proper powder handling and the detrimental effects that even small amounts of contaminants can have on AM-produced components. 

Decisions about extinction risks are ubiquitous in everyday life and for our continued existence as a species. We introduce a new risky-choice task that can be used to study this topic: The Extinction Gambling Task. Here, we investigate two versions of this task: a Keep variant, where participants cannot accumulate any more earnings after the extinction event, and a Lose variant, where extinction also wipes out all previous earnings. We derive optimal solutions for both variants and compare them to behavioural data. Our findings suggest that people understand the difference between the two variants and their behaviour is qualitatively in line with the optimal solution. Further, we find evidence for risk-aversion in the Keep condition but not in the Lose condition. We hope that this task can facilitate further research on this vital topic. 

Abstract In order to investigate the in‐space in situ resource utilization, directed energy deposition (DED)‐based additive manufacturing (AM) has been utilized to process Martian regolith—Ti6Al4V (Ti64) composites. Here we investigated the processability of depositing 5, 10, and 100 wt% of Martian regolith premixed with Ti6Al4V using laser‐based DED, analyzing the printed structure via X‐ray diffraction, Vicker's microhardness, scanning electron microscopic imaging, and wear characteristics utilizing an abrasive water jet cutter to simulate abrasive environments on the Martian surface. The results indicate that the surface roughness and hardness of the composites increase with respect to the Martian regolith’ weight percentage due to in situ ceramic reinforcement. For instance, i5‐wt% addition of Martian regolith increased the Vicker's microhardness from 366 ± 6 HV_0.2for as‐printed Ti64 to 730 ± 27 HV_0.2while maintaining similar abrasive wear performance as Ti6Al4V. The results point toward laser‐based AM for fabricating Ti64—Martian regolith composites with comparable properties. The study also reveals promising results in limiting the mass burden for future space missions, resulting in cheaper and easier launches.