Delroisse, Pauline
[UCL]
Rigo, Olivier
[Sirris, Seraing, Belgique]
Doneux, Catherine
[UCL]
Wevers, Martine
[KUL, Leuven, Belgique]
Godet, Stéphane
[Ecole Polytechnique de Bruxelles, Bruxelles, Belgique]
Jacques, Pascal
[UCL]
Simar, Aude
[UCL]
Following the growing development of additive manufacturing techniques, the processing of small lightweight open-cell structures is now facilitated. However, the consequences of the specific microstructure and geometrical features of such structures on their mechanical properties and in particular on their impact resistance require further investigations. In the present project, two topologies of structures are studied: bulk samples 10x10x10 mm³ in size and lattices with body centred cubic cores (BCC), with a strut diameter of 0.6 mm and unit cell comprised in a cube of 4 mm side. Both are made of AlSi10Mg and obtained by additive manufacturing, more specifically by laser beam melting (LBM). This new manufacturing technology involves some challenges specific to aluminum alloys. Indeed, aluminum powder oxidizes after recycling. The relationship between the powder oxidation and the formation of defects will be discussed. In addition, the influence on the microstructure and defects of other key contributing factors during the process such as scan velocity, hatch space and thickness of the layers are evidenced. Moreover depending on the sample type, the gradient of the temperature and the solidification rate are quite different. The microstructure of the bulks and the lattices are compared. The impact resistance of the lattice sandwiches is measured and the collapse mechanisms of the structures impacted at fixed energies is studied, with the help of X-ray computed tomography. The consequences of the defect formation and the geometrical features specific to LBM lattice are discussed.


Bibliographic reference |
Delroisse, Pauline ; Rigo, Olivier ; Doneux, Catherine ; Wevers, Martine ; Godet, Stéphane ; et. al. Aluminum lattice structures processed by additive manufacturing: microstructure and impact resistance.EUROMAT 2015 (Warsaw, Poland, du 20/09/2015 au 24/09/2015). |
Permanent URL |
http://hdl.handle.net/2078.1/161543 |