De Silva, S. T.TanushiDoblin, ChristianGulizia, StefanCole, IvanToh, Rou Jun2026-06-112026-06-110032-5910ORCID:/0000-0001-6582-1457/work/217149515https://hdl.handle.net/1885/733810449The cost of additive manufacturing can be reduced if economical non-spherical powders are used. However, current flowability tests are inadequate to determine whether these powders can flow and spread well in powder bed systems. This paper presents a novel tool called the Universal Powder Bed designed to analyse the layer-spreading process of an electron beam melting system. The spreadability and feasibility of using a novel bimodal powder comprising of irregularly shaped tantalum and spherical titanium is investigated against three measures: area fraction of build surface covered with powder, surface roughness and composition of the powder bed. The characterisation techniques revealed that increasing layer thicknesses and slower rake speeds produced more efficiently packed powder layers and decreased the effects of segregation between opposite sides of the powder bed. This study shows that despite the segregation observed with bimodal powders, acceptable levels of spreadability can be produced by refining the spreading parameters.This work was financially supported by the RMIT-CSIRO Research Master's Scholarship Program . The authors would like to sincerely thank the members of the Materials Characterisation and Modelling Program at CSIRO, in particular Chris Sheedy, Winston Liew, and Hayley Meyer for their invaluable support and contribution in performing the chemical analyses for this project. Additionally, we would also like to thank Sherman Wong and Sheridan Mayo for their assistance in micro-CT scanning all the samples for this project. The first author is grateful for the time and efforts that have been spent in producing these significant time-consuming results for the project. This work was financially supported by the RMIT-CSIRO Research Master's Scholarship Program.enPublisher Copyright: © 2023Bimodal powdersNon-spherical mixturesPowder bed fusion systemsSegregationSpreadabilityTitanium‑tantalum2023-10-0110.1016/j.powtec.2023.11879385166207082