Abstract
Despite the wide application of powder metallurgy in the field of additive manufacturing, a general understanding of the spreadability of powder particles in electron beam powder bed fusion (EB-PBF) is lacking. This paper presents the results of a literature review on particle flowability and spreading in additive processes. Different flowability tests are described and spreading mechanisms for different powder-bed processes are reviewed. A technique is proposed to study spreadability in which a single layer of powder is ‘frozen’ in the as-spread condition by contact sintering and then characterized using white-light interferometry. A standard method to calculate powder-bed density is defined based on this approach, and correlations between density, packing factor, and flowability are established.
