Page - 52 - in 3D Printing of Metals

metals Article ComparisonofSingleTi6Al4VStrutsMadeUsing SelectiveLaserMeltingandElectronBeamMelting Subject toPartOrientation VolkerWeißmann1,2,*,PhilippDrescher3,RainerBader2,HermannSeitz 3,HaraldHansmann1 andNicoLaufer 4 1 FacultyofEngineering,UniversityofAppliedScience,Technology,BusinessandDesign, Philipp-Müller-Str. 14,23966Wismar,Germany;h.hansmann@ipt-wismar.de 2 BiomechanicsandImplantTechnologyResearchLaboratory,DepartmentofOrthopedics, UniversityMedicineRostock,DoberanerStrasse142,18057Rostock,Germany; rainer.bader@med.uni-rostock.de 3 FluidicTechnologyandMicrofluidics,FacultyofMechanicalEngineeringandMarineTechnology, UniversityofRostock,18059Rostock,Germany;philipp.drescher@uni-rostock.de (P.D.); hermann.seitz@uni-rostock.de (H.S.) 4 Institute forPolymerTechnologiese.V.,AlterHolzhafen19,23966Wismar,Germany; laufer@ipt-wismar.de * Correspondence:weissmann@ipt-wismar.de;Tel.:+49-03841-758-2388;Fax:+49-03841-758-2399 AcademicEditor:ManojGupta Received: 1December2016;Accepted: 9March2017;Published: 11March2017 Abstract: The use of additivemanufacturing technologies to produce lightweight or functional structures iswidespread. Especially Ti6Al4V plays an important role in this development field andpartsaremanufacturedandanalyzedwith theaimtocharacterize themechanicalproperties of open-porous structures and to generate scaffolds with properties specific to their intended application. AnSLMandanEBMprocesswereused respectively to fabricate theTi6Al4Vsingle struts. Formechanical characterization,uniaxial compression testsandhardnessmeasurementswere conducted. Furthermore, thestrutsweremanufacturedindifferentorientations for thedetermination of themechanicalproperties. Roughnessmeasurementsandamicroscopiccharacterizationof the strutswerealsocarriedout. Somepartswerecharacterizedfollowingheat treatment (hot isostatic pressing).Afunctionalcorrelationwas foundbetweenthecompressivestrengthandtheslenderness ratio (λ) as well as the equivalent diameter (d) and the height (L) of EBM and SLM parts. Hardness investigationsrevealedconsiderabledifferences related to themicrostructure.Aninfluence of heat treatment aswell as of orientation could be determined. In thiswork, we demonstrate the influence of the fabricationquality of single struts, the roughness and themicrostructure on mechanicalpropertiesasa functionoforientation. Keywords:Ti6Al4V;selectivelasermelting;electronbeammelting;singlestrut;mechanicalproperties 1. Introduction The development of structures usingmodernAM (additivemanufacturing) technologies is asteadilygrowingresearchfield inrecentyears.Here, complexandweight-savingstructuresarouse special interest.One importantgoal is frequently the targeteddimensioningofmechanicalproperties. The progress in additivemanufacturing technologymakes thismore tangible. An essential prerequisite is to develop a better understanding of the technological contexts of additive manufacturingtechnologies. Of strong interest is the relationship between the materials used, the process parameters, especially in the applicationfield of open-porous load-bearing lattice structures, and their effects Metals 2017,7, 91 52 www.mdpi.com/journal/metals