This paper deals with various selective laser melting (SLM) processing strategies for aluminum 2618 powder in order to get material densities and properties close to conventionally-produced, high-strength 2618 alloy. To evaluate the influence of laser scanning strategies on the resulting porosity and mechanical properties a row of experiments was done. Three types of samples were used: single-track welds, bulk samples and samples for tensile testing. Single-track welds were used to find the appropriate processing parameters for achieving continuous and well-shaped welds. The bulk samples were built with different scanning strategies with the aim of reaching a low relative porosity of the material. The combination of the chessboard strategy with a 2 × 2 mm field size fabricated with an out-in spiral order was found to eliminate a major lack of fusion defects. However, small cracks in the material structure were found over the complete range of tested parameters. The decisive criteria was the elimination of small cracks that drastically reduced mechanical properties. Reduction of the thermal gradient using support structures or fabrication under elevated temperatures shows a promising approach to eliminating the cracks. Mechanical properties of samples produced by SLM were compared with the properties of extruded material. The results showed that the SLM-processed 2618 alloy could only reach one half of the yield strength and tensile strength of extruded material. This is mainly due to the occurrence of small cracks in the structure of the built material.

Institute of Machine and Industrial Design Faculty of Mechanical Engineering Brno University of Technology 616 69 Brno Czech Republic

Institute of Materials Science and Engineering Faculty of Mechanical Engineering Brno University of Technology 616 69 Brno Czech Republic

Institute of Physical Engineering Faculty of Mechanical Engineering Brno University of Technology 616 69 Brno Czech Republic

Institute of Production Engineering Faculty of Mechanical Engineering and Economic Sciences Graz University of Technology 8010 Graz Austria

Zobrazit více v PubMed

Wohlers T.T., Caffrey T. Wohlers Report 2015: 3D Printing and Additive Manufacturing State of the Industry Annual Worldwide Progress Report. Wohlers Associates; Fort Collins, CO, USA: 2015.

Ceschini L., Morri A., Morri A., Sabatino M.D. Effect of thermal exposure on the residual hardness and tensile properties of the EN AW-2618A piston alloy. Mater. Sci. Eng. A. 2015;639:228–297. doi: 10.1016/j.msea.2015.04.080. DOI

Buchbinder D., Schleifenbaum H., Heidrich S., Meiners W., Bültmann J. HighPower Selective Laser Melting (HP SLM) of Aluminum Parts. Phys. Procedia. 2011:271–278. doi: 10.1016/j.phpro.2011.03.035. DOI

Olakanmi E.O. Selective laser sintering/melting (SLS/SLM) of pure Al, Al–Mg, and Al–Si powders: Effect of processing conditions and powder properties. J. Mater. Process. Technol. 2013;213:1387–1405. doi: 10.1016/j.jmatprotec.2013.03.009. DOI

Aboulkhair N.T., Everitt N.M., Ashcroft I., Tuck C.H. Reducing porosity in AlSi10Mg parts processed by selective laser melting. Addit. Manuf. 2014:77–86. doi: 10.1016/j.addma.2014.08.001. DOI

Manfredi D., Calignano F., Krishnan M., Canali R., Ambrosio E.P., Biamino S., Ugues D., Pavese M., Fino P. Additive Manufacturing of Al Alloys and Aluminium Matrix Composites (AMCs) In: Monteiro W.A., editor. Light Metal Alloys Applications. InTech; London, UK: 2014. pp. 3–34.

Manfredi D., Calignano F., Krishnan M., Canali R., Ambrosio E.P., Atzeni E. From powders to dense metal parts: Characterization of a commercial AlSiMg alloy processed through direct metal laser sintering. Materials. 2013;6:856–869. doi: 10.3390/ma6030856. PubMed DOI PMC

Thijs L., Kempen K., Kruth J.-P., van Humbeeck J. Fine-structured aluminium products with controllable texture by selective laser melting of pre-alloyed AlSi10Mg powder. Acta Mater. 2013;61:1809–1819. doi: 10.1016/j.actamat.2012.11.052. DOI

Kempen K., Thijs L., van Humbeeck J., Kruth J.-P. Mechanical Properties of AlSi10Mg Produced by Selective Laser Melting. Phys. Procedia. 2012;39:439–446. doi: 10.1016/j.phpro.2012.10.059. DOI

Prashanth K.G., Scudino S., Klauss H.J., Surreddi K.B., Löber L., Wang Z., Chaubey A.K., Kühn U., Eckert J. Microstructure and mechanical properties of Al–12Si produced by selective laser melting: Effect of heat treatment. Mater. Sci. Eng. A. 2014;590:153–160. doi: 10.1016/j.msea.2013.10.023. DOI

Read N., Wang W., Essa K., Attallah M.M. Selective laser melting of AlSi10Mg alloy: Process optimisation and mechanical properties development. Mater. Des. 2015;65:417–424. doi: 10.1016/j.matdes.2014.09.044. DOI

Siddique S., Imran M., Wycisk E., Emmelmann C., Walther F. Influence of process-induced microstructure and imperfections on mechanical properties of AlSi12 processed by selective laser melting. J. Mater. Process. Technol. 2015;221:205–213. doi: 10.1016/j.jmatprotec.2015.02.023. DOI

Brandl E., Heckenberger U., Holzinger V., Buchbinder D., Gu D. Additive manufactured AlSi10Mg samples using Selective Laser Melting (SLM): Microstructure, high cycle fatigue, and fracture behavior. Materials. 2012;34:175–199. doi: 10.1016/j.matdes.2011.07.067. DOI

Ming T.P., Pistorius C.H. Oxides, porosity and fatigue performance of AlSi10Mg parts produced by selective laser melting. Int. J. Fatigue. 2015;93:192–201.

Shafaqat S., Imran M., Walther F. Very high cycle fatigue and fatigue crack propagation behavior of selective laser melted AlSi12 alloy. Int. J. Fatigue. 2017;94:246–254.

Li W., Li S., Liu J., Zhang A., Zhou Y., Wei Q., Yan C.H., Shi Y. Effect of heat treatment on AlSi10Mg alloy fabricated by selective laser melting: Microstructure evolution, mechanical properties and fracture mechanism. Mater. Sci. Eng. A. 2016;663:116–125. doi: 10.1016/j.msea.2016.03.088. DOI

Karg M., Ahuja B., Schmidt M. Processability of high strength Aluminium-Copper alloys AW-2022 and 2024 by Laser Beam Melting in Powder Bed. In: Bourrell D., editor. Proceedings of the 25th Annual International Solid Freeform Symposium; Austin, TX, USA. 4–6 August 2014; pp. 420–436.

Ahuja B., Karg M., Nagulin K.Y., Schmidt M. Fabrication and Characterization of High Strength Al-Cu Alloys Processed Using Laser Beam Melting in Metal Powder Bed. Phys. Procedia. 2014;56:135–146. doi: 10.1016/j.phpro.2014.08.156. DOI

Zhang H., Zhu H., Qi T., Hu Z., Zeng X. Selective laser melting of high strength Al–Cu–Mg alloys: Processing, microstructure and mechanical properties. Mater. Sci. Eng. A. 2016;656:47–54. doi: 10.1016/j.msea.2015.12.101. DOI

Karg M., Ahuja B., Schaub A., Schmidt J., Sachs M., Mahr A., Wiesenmayer S., Wigner L., Wirth K., Peukert W., et al. Effect of process conditions on mechanical behavior of aluminium wrought alloy EN AW-2618 additively manufactured by Laser Beam Melting in powder bed; Proceedings of the Lasers in Manufacturing Conference; Munchen, Germany. 22–25 June 2015.

Lu Y., Wu S., Gan Y., Huang T., Yang C., Junjie L., Lin J. Study on the microstructure, mechanical property and residual stress of SLM Inconel-718 alloy manufactured by differing island scanning strategy. Opt. Laser Technol. 2015;75:197–206. doi: 10.1016/j.optlastec.2015.07.009. DOI

Carter L.N., Martin C., Withers P.J., Attallah M.M. The influence of the laser scan strategy on grain structure and cracking behaviour in SLM powder-bed fabricated nickel superalloy. J. Alloys Compd. 2014;615(Suppl. C):338–347. doi: 10.1016/j.jallcom.2014.06.172. DOI

Popovich V.A., Borisov E.V., Popovich A.A., Sufiiarov V.S., Masaylo D.V., Alzina L. Functionally graded Inconel 718 processed by additive manufacturing: Crystallographic texture, anisotropy of microstructure and mechanical properties. Mater. Des. 2017;114(Suppl. C):441–449. doi: 10.1016/j.matdes.2016.10.075. DOI

Koutný D., Paloušek D., Koukal O., Zikmund T., Pantělejev L. Processing of High Strength Al-Cu alloy Using 400 W Selective Laser Melting—Initial Study; Proceedings of the Lasers in Manufacturing Conference; Munchen, Germany. 22–25 June 2015.

Koukal O., Koutný D., Paloušek D., Vrána R., Zikmund T., Pantělejev L. Research about the Influence of Process Parameters of Selective Laser Melting on Material EN AW 2618; Proceedings of the Euro PM; Reims, France. 4–7 October 2015.

EN 573-3—Aluminium and Aluminium Alloys—Chemical Composition and form of Wrought Products, Part 3: Chemical Composition and Form of Products. European Committee for Standardization; Brussels, Belgium: 2013.

Pantělejev L., Koutný D., Paloušek D., Kaiser J. Mechanical and Microstructural Properties of 2618 Al-Alloy Processed by SLM Remelting Strategy. Mater. Sci. Forum. 2016;891:343–349. doi: 10.4028/www.scientific.net/MSF.891.343. DOI

Trapp J., Rubenchik A.M., Guss G., Matthews M. In situ absorptivity measurements of metallic powders during laser powder-bed fusion additive manufacturing. Appl. Mater. Today. 2017;9:341–349. doi: 10.1016/j.apmt.2017.08.006. DOI

Olakanmi E.O., Cochrane R.F., Dalgarmo K.W. A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing, microstructure, and properties. Prog. Mater. Sci. 2015;74:401–477. doi: 10.1016/j.pmatsci.2015.03.002. DOI

Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting

Dynamic Loading of Lattice Structure Made by Selective Laser Melting-Numerical Model with Substitution of Geometrical Imperfections

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