Autor: |
Ziyad Smoqi, Benjamin D. Bevans, Aniruddha Gaikwad, James Craig, Alan Abul-Haj, Brent Roeder, Bill Macy, Jeffrey E. Shield, Prahalada Rao |
Jazyk: |
angličtina |
Rok vydání: |
2022 |
Předmět: |
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Zdroj: |
Materials & Design, Vol 215, Iss , Pp 110508- (2022) |
Druh dokumentu: |
article |
ISSN: |
0264-1275 |
DOI: |
10.1016/j.matdes.2022.110508 |
Popis: |
The objective of this work is to mitigate flaw formation in powder and laser-based directed energy deposition (DED) additive manufacturing process through close-loop control of the meltpool temperature. In this work, the meltpool temperature was controlled by modulating the laser power based on feedback signals from a coaxial two-wavelength imaging pyrometer. The utility of closed-loop control in DED is demonstrated in the context of practically inspired trapezoid-shaped stainlesssteel parts (SS 316L). We demonstrate that parts built under closed-loop control have reduced variation in porosity and uniform microstructure compared to parts built under open-loop conditions. For example, post-process characterization showed that closed-loop processed parts had a volume percent porosity ranging from 0.036% to 0.043%. In comparison, open-loop processed parts had a larger variation in volume percent porosity ranging from 0.032% to 0.068%. Further, parts built with closed-loop processing depicted consistent dendritic microstructure. By contrast, parts built with open-loop processing showed microstructure heterogeneity with the presence of both dendritic and planar grains, which in turn translated to large variation in microhardness. |
Databáze: |
Directory of Open Access Journals |
Externí odkaz: |
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