Microstructure of aluminum alloys manufactured via laser powder bed fusion: A review

Abstract

Laser powder bed fusion (LPBF) enables layer-by-layer manufacturing and provides distinguished microstructure compared with conventional processing methods. Microstructure controlling of LPBF parts requires deep insights into the solidification process. The aim of this article is to review the solidification fundamentals and microstructure characteristics during the LPBF process, and to serve as a guide on how to tailor microstructure for a given part. To clarify the distinguished microstructural characteristics of LPBF parts, casting is briefly discussed for comparison. The article begins with the introduction of solidification theory and microstructure features in LPBF and casting. Thereafter, the attempts to tailor microstructure in LPBF and casting are addressed and compared. The final part of this paper provides an outlook on the remaining challenges and potential research topics of microstructure controlling in LPBF with Al alloys.