Selective Laser Melting Strategy for Fabrication of Thin Struts Usable in Lattice Structures

Radek Vrána; Daniel Koutný; David Paloušek; Libor Pantělejev; Jan Jaroš; Tomáš Zikmund; Jozef Kaiser

doi:10.3390/ma11091763

Selective Laser Melting Strategy for Fabrication of Thin Struts Usable in Lattice Structures

Materials (Basel). 2018 Sep 18;11(9):1763. doi: 10.3390/ma11091763.

Authors

Radek Vrána¹, Daniel Koutný², David Paloušek³, Libor Pantělejev⁴, Jan Jaroš⁵, Tomáš Zikmund⁶, Jozef Kaiser⁷

Affiliations

¹ Brno University of Technology, Faculty of Mechanical Engineering, Institute of Machine and Industrial Design, Technická 2896/2, 616 69 Brno, Czech Republic. Radek.Vrana@vut.cz.
² Brno University of Technology, Faculty of Mechanical Engineering, Institute of Machine and Industrial Design, Technická 2896/2, 616 69 Brno, Czech Republic. Daniel.Koutny@vut.cz.
³ Brno University of Technology, Faculty of Mechanical Engineering, Institute of Machine and Industrial Design, Technická 2896/2, 616 69 Brno, Czech Republic. David.Palousek@vut.cz.
⁴ Brno University of Technology, Faculty of Mechanical Engineering, Institute of Materials Science and Engineering, Technická 2896/2, 616 69 Brno, Czech Republic. Libor.Pantelejev@vut.cz.
⁵ Brno University of Technology, Faculty of Mechanical Engineering, Institute of Machine and Industrial Design, Technická 2896/2, 616 69 Brno, Czech Republic. Jan.Jaros@vut.cz.
⁶ Brno University of Technology, Central European Institute of technology BUT, Purkyňova 123, 612 00 Brno, Czech Republic. Tomas.Zikmund@vut.cz.
⁷ Brno University of Technology, Central European Institute of technology BUT, Purkyňova 123, 612 00 Brno, Czech Republic. Jozef.Kaiser@vut.cz.

Abstract

This paper deals with the selective laser melting (SLM) processing strategy for strut-lattice structure production which uses only contour lines and allows the porosity and roughness level to be managed based on combination of the input and linear energy parameters. To evaluate the influence of a laser scanning strategy on material properties and surface roughness a set of experiments was performed. The single welds test was used to find the appropriate processing parameters to achieve continuous welds with known width. Strut samples were used to find a suitable value of weld overlapping and to clarify the influence of input and linear laser energy on the strut porosity and surface roughness. The samples of inclined hollow struts were used to compare the wall thickness with single welds width; the results showed about 25% wider welds in the case of a hollow strut. Using the proposed SLM strategy it is possible to reach a significantly lower porosity and surface roughness of the struts. The best results for struts with an inclination of 35.26° were achieved with 25% track overlapping, input energy in the range from 9 J to 10.5 J and linear energy E_lin from 0.25 to 0.4 J/mm; in particular, the relative density of 99.83% and the surface roughness on the side of the strut of Ra 14.6 μm in an as-built state was achieved.

Keywords: AlSi10Mg aluminum alloy; contour strategy; input energy; linear energy; melt-pool size; porosity; roughness; scanning strategy; selective laser melting (SLM).