CRACKING BEHAVIOR OF A ZR-BLENDED AL-ZN-MG ALLOY PROCESSED BY POWDER BED FUSION OF METALS USING A LASER BEAM UNDER DIFFERENT PROCESS GAS MIXTURES

This study aims to investigate the influence of different process gases on the processing of a Zrblended aluminum 7075 alloy by powder bed fusion of metals using a laser beam. Two common gases for this process, argon and nitrogen, were compared. The objective was to study the effect of the gases on the crack formation in the bulk material with respect to the possible formation of nitrides. To assess this phenomenon, cuboids at different heights were printed with an in-situ change of the process gas in steps from pure argon to pure nitrogen. During the post-process analysis, special focus was placed on investigating the crack formation. The preliminary results on specimens from initial build jobs showed differences in the cracking behavior with a varying amount of nitrogen in the process gas. A higher amount of cracking was found in the specimens produced with pure nitrogen compared to the specimens fabricated under pure argon atmosphere. This may be attributed to the formation of crackinducing zirconium nitrides.     «

This study aims to investigate the influence of different process gases on the processing of a Zrblended aluminum 7075 alloy by powder bed fusion of metals using a laser beam. Two common gases for this process, argon and nitrogen, were compared. The objective was to study the effect of the gases on the crack formation in the bulk material with respect to the possible formation of nitrides. To assess this phenomenon, cuboids at different heights were printed with an in-situ change of the process...     »