Powder Surface Chemistry and Its Effect on Cracking Behavior in Aluminum Alloys Fabricated by LPBF

The printability of aluminum alloys in laser powder bed fusion (LPBF) depends on the interplay between material properties, powder characteristics, and processing conditions. Among the most persistent challenges is micro-cracking, which limits the range of alloys that can be processed successfully and can compromise the structural integrity of printed parts. This is evident in high-crack-susceptibility aluminum alloys, whose processing remains difficult under the rapid solidification conditions inherent to LPBF. While cracking is commonly associated with alloy composition and solidification behavior, the influence of powder surface chemistry has received less attention. This work explores the effect of surface chemistry on the microstructural evolution of aluminum alloys with varying crack susceptibility during LPBF, with a focus on its relation to crack formation, propagation, and density. The findings highlight powder surface chemistry as a factor to consider to better understand the printability of crack-susceptible aluminum alloys.