|Sivaji Karna, Lang Yuan, Andrew Gross, Tianyu Zhang, Rimah Al-Aridi, Faith Buchanan, Timothy Krentz, Dale Hitchcock
AA 6061 is one of the most commonly used aluminum alloys in aerospace and automotive applications. However, applications of additively manufactured AA 6061 via the laser powder bed fusion (LPBF) process are limited, owing to the formation of extensive pores and cracks during the rapid solidification. In this study, bead-on-plate experiments, informed by numerical simulations based on Rosenthal solutions, covering a wide range of cooling rates, were performed to understand the melt pool behavior, including size and stability. Process parameters were then selected to print cubic samples. Samples are characterized using microscopy techniques. Samples with a relative density higher than 99.5 % were achieved with high power, high scan speed, and relatively low energy density. Cracks were observed in all samples, and the influence of the process parameters on crack initiation, size, and distribution was analyzed. Lastly, methods to mitigate crack formation, such as heated bed are discussed.