Page - 55 - in 3D Printing of Metals

Metals 2017,7, 91 thematerial fractionandtheenergyappliedduringmanufacturing. Thesinglestrutsarepositioned betweenthesetwoareas.Allpartsaredesignedwithfoursymmetricallyarrangedsinglestruts. Forthe determinationof themechanical characteristics in thecompressiontest, thedimensionsof thestrut specimenweremodifiedin twoways. Thegeometricparameters for the investigatedstrutspecimen are listed inTable1. Figure2. Structuraldesignof the single strut specimen. The test specimenconsists of twoparallel areas (baseandtop)andfoursinglestruts. Thesinglestrutsarearrangedatanangleof90degrees to thebaseandtoparea. Thecrossoversbetweenthebaseandtoparea to thesinglestrutareproduced witharadiusof1mm. Table1.Overviewof thegeometricparameters for thestrutspecimen.Afirstvariationwithconstant diameter (d) andvariableheightandasecondvariationwithconstantheight (L) andvariablediameter weredesigned.Allotherparameters inbothserieswereconstant.AllvalueswerederivedfromCAD dataandaregiven inmm. Variation1 Variation2 HeightL (mm) HeightL (mm) 12 10 8 6 12 Diameterd (mm) Diameterd (mm) 1.1 1.1 1.3 1.5 1.7 2.2. Fabricationof theScaffoldsvia theSLMProcessand theEBMProcess In thiswork, all partswere built via the SLMprocess and theEBMprocess. Figure 3 shows the experimental design. The aim of the experimental plan was to obtain the greatest possible information from the smallest possible number of tests. Figure 4 shows representative parts of the twomanufacturingprocesses inassociationwithbuildingorientation. Figure3. Overviewofallmanufacturedparts aswell asheat treatment conditionsandorientation. Partswerebuiltforcompressiontesting(SLM(HIP)andEBM(NoHIP)d-andL-constant;SLM(NoHIP) d-constantandL1/d1), fabricationaccuracy,determiningcrosssectionareas,hardnessandroughness. 55