Sensitivity of additively manufactured AA7075 to variation in feedstock composition and print parameters

We developed a combined finite element and CALPHAD based model of the Laser Powder Bed Fusion (LPBF) process for AA7075 alloy that considers the effect of feedstock composition and print parameters. A single-pass of a laser on a layer of AA7075 alloy powder has been considered. Sensitivity of temperature evolution and melt pool geometry to variation in the stoichiometry of the feedstock powder and laser source characteristics have been studied. Our results indicate that deviation (up to 10%) of the feedstock composition from the AA7075 raises the maximum temperature and increases melt pool size. Excess Cu content shows the largest melt pool width and depth among all the cases. The peak temperature is higher than the standard feedstock composition in all cases, except when the Cu concentration is reduced. Increasing the scan power also results in a higher peak temperature and a larger melt pool size. Furthermore, the temperature's rise time increases by lowering the scan speed.

Automated summary

The study developed a model for the LPBF process of AA7075 alloy considering feedstock composition and print parameters. Results showed that deviation in feedstock composition raises maximum temperature and melt pool size. Excess Cu content led to the largest melt pool dimensions. Increasing scan power resulted in higher peak temperature and larger melt pool. Lowering scan speed increased temperature rise time.