Page - 92 - in 3D Printing of Metals

Metals 2016,6, 280 Themainsteps includethreeaspectsas follows: 1.Designof theskin Asuitableskinthicknessofthecomponents isnecessarytomaintaintheshapeofparts. Thispaper studiedthestrainandstressofpartswithdifferentskin thicknessesandloads. 2. Partsdisassemblyandframeworkdesign Thecomponentsweredisassembledby their shapeand force conditions. Differentoptimized frameworkswereselectedfromtheframework libraryorwerenewlydesignedtofill thedisassembled parts. Thesenewlydesignedframeworkscanbereservedat the framework librarybytheir shapeand load. Useof the framework librarycangreatly shorten thedesignperiodcomparedwith topology optimizationof thewholepart. Thedesignof newparts canbe as easy as selecting fundamental frameworks tofill theparts. 3. Finiteelementanalysisanddetailsofparts Weassembledthedividedparts togetherby their topologystructureandstudythecharacteristics ofcomponentsusingthefiniteelementmethod. Improve thedetails suchas themetaloutletposition of themetalpowderaccordingto theSLMprocess. 3.1.DesignofSkin Thequalityof thin-wallpartsmanufacturedbytheSLMprocesswillbeaffectedbytheir thickness. The thicker the thin-wallpartsare, thebetter thequalitywillbe.However, thickwallswillbringabout ahigherweightof thecomponents,whichmakes itdifficult toget lightweightparts. Theoptimum thicknessof theskinwasstudiedbythefiniteelementanalysisofanemptycubewithdifferent loads andwall thicknessesasshowninFigure6. Figure6.Modelof thin-wallparts forfiniteelementanalysis. Theside lengthof thecube is100mm. Thebottomsidewasfixedanduniformloadsof500N and1000Nwereapplied, respectively, to the topside to test themechanicalperformanceofdifferent thinwallsundervarious loads. Theresultsof thefiniteelementanalysisarereported inTable1and Figures7and8. Table1.Analysis resultof thin-wallpartswithdifferent thicknessesandloads. Thickness (mm) Load(N) MaximumStress (MPa) MaximumStrain(mm) Weight (g) 0.5 500 112.4 0.73937 2381000 290.75 2.028 1 500 68.054 0.37832 4701000 148.36 0.75461 1.5 500 35.469 0.13709 6991000 70.939 0.27418 92