Study and development of fusion strategies for support-less manufacturing with Electron Beam Powder Bed Fusion technology

Villatoro Funez, Cesar Noe (author), Klobčar, Damjan (mentor), Ugues, Daniele (comentor), Doutre, Prierre-Thomas (comentor)

Overhang regions in Electron Beam Powder Bed Fusion (EB-PBF) are prone to defects like warping, curling or side loss due to poor heat dissipation and residual stresses. Traditionally, defects are mitigated by support structures that introduce material waste and post-processing operations. This study investigates whether adjusting fusion strategies and energy input parameters can reduce overhang defects without the use of supports. A series of experiments were conducted on an ARCAM A1 machine in which multiple fusion strategies, process parameters, energy densities and build themes were studied when building without support structures. Results show that optimized parameters and an optimized fusion strategy of Quad Islands can achieve the best results in terms of geometric accuracy, drastically eliminating warping and side loss defects. This improvement, however, comes at the expense of an increase in the part porosity.

• Language: English
• Keywords: powder bed fusion, additive manufacturing, electron beams, supports, defects, porosity, warping
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2025
• Number of pages: XXVIII, 89 str.
• PID: 20.500.12556/RUL-175020
• UDC: 621.791.722:621.7.019:004.925.8(043.2)
• COBISS.SI-ID: 261444867
• Publication date in RUL: 14.10.2025

Secondary language

• Language: Slovenian
• Title: Študija in razvoj strategij dodajalne izdelave brez podpor s spajanjem prahu na podlago z elektronskim snopom

Abstract

Previsna območja pri taljenju prahu z elektronskim žarkom (EB-PBF) so nagnjena k napakam, kot so upogibanje, zvijanje ali manko materiala zaradi slabega odvajanja toplote in zaostalih napetosti. Tradicionalno se morebitne napake med izdelavo odpravlja s podpornimi strukturami, ki povzročajo izmet materiala, in zahtevajo naknadno obdelavo. Ta študija raziskuje, ali lahko prilagajanje strategij in parametrov 3D tiska zmanjša napake pri izdelavi izdelkov s previsom brez uporabe podpor. Na stroju ARCAM A1 je bila izvedena parametrična analiza, v katerih smo preučevali vpliv strategij 3D tiska, procesnih parametrov, gostote energije pri dodajalni izdelavi brez podpornih struktur. Rezultati kažejo, da lahko optimizirani parametri in optimizirana strategija zlitja ang. Quad Islands dosežejo najboljše rezultate v smislu geometrijske natančnosti, kar drastično odpravi napake zvijanja in stranskih izgub materiala. Vendar pa se z izboljšanjem geometrije v izdelku pojavi več poroznosti.

• Keywords: taljenje prahu na podlago, dodajalna izdelava, elektronski snopi, podporne strukture, napake, poroznost, deformacije