Page - 143 - in 3D Printing of Metals

Metals 2017,7, 113 5.Conclusions Inthepresentstudy, itwasexploredwhetheradditivemanufacturing, i.e., lasercladding,couldbe usedtomanufactureflexiblyapplicable localpatches to locally increase thestiffnessor thicknessof a sheetmetal blankor sheetmetal component. The following conclusions canbedrawn fromthe presentedresults: • Laser claddingcanbeused to locally reinforce sheetmetal blankswith respect to lightweight designconsiderations. Theresultingtailored laser-claddedblanksareanewtypeof lightweight materialwhichcanbedesignedsuchthat theyoutperformcurrentlyavailable tailoredblanks in lightweightdesignperformance. • Limited formabilitywas observed to be themain obstacle of applying tailored laser-cladded blanks as semi-finishedproducts.While the case study in the paper focuses onAl-Si of low formability, formabilityof laser-cladmaterial couldbe improvedusingweldablewroughtalloys andheat treatmentprior to forming. • Laser cladding may also be used for stiffness management of already formed components. However, theresultsofapuresizingoptimizationmaynotbemanufacturedwithoutdistortion, whichseemstobe themain limitingfactor for lasercladdingonformedcomponents. • Aconstrainedsizingoptimizationledtoadesignwithminimumdangerofdistortionbutreduced stiffness increasecomparedto theoptimumfoundbysizingoptimization. • Applicationofadditivemanufacturing insheetmetal formingofferspotentials fordeveloping newproductssuchas tailored laser-claddedblanksandfordevelopingnewlightweightdesign methods such as stiffness management of components, by integrating sizing optimization, distortioncontrolandlasercladding. Futureworkshouldalsoexploreotherapplicationsofadditivelymanufacturedfeaturesonsheet metal components, i.e., functional features such as electrical contacts, pedestals or transitions to bulkcomponents. Acknowledgments: The depicted results were achieved to a great extent in the project “Materialeffiziente Herstellung belastungsangepasster Blechbauteile mit durch Laseradditiv aufgebrachten flexiblen Verstärkungszonen” (Ref.-No. AiF 19292BG), which is financed and supervised by the European Research Association for SheetMetalWorking (EFB). In the scope of theprogramme topromote Industrial Collective Researchtheywere fundedbytheGermanFederationof IndustrialResearchAssociations (AiF)withmeansof the FederalMinistryofEconomicAffairsandEnergy(BMWi)onthebasisofadecisionbytheGermanBundestag. This funding isgratefullyacknowledged. Author Contributions: Bambach, M. devised the applications and experiments, performed the numerical simulationsandwroteandedited themanuscript;Sviridov,A.performedthe formingexperimentsandanalyzed the experimental data; Weisheit, A. and Schleifenbaum, J.H. performed the laser cladding experiments of demonstrator I, themetallographicanalysisandinterpretedtheresults. Conflictsof Interest:Theauthorsdeclarenoconflictof interest. References 1. Merklein,M.; Johannes,M.;Lechner,M.;Kuppert,A.Areviewontailoredblanks—Production,applications andevaluation. J.Mater. Process. Technol. 2014,214, 151–164. [CrossRef] 2. Buchmayr,B.;Figala,G.;Wunsch,K.Lokale fertigungstechnischeVerstärkungskonzeptezurErhöhungder Materialeffizienz.BHMBergHüttenmännischeMonatshefte2010,155, 307–312. (InGerman). [CrossRef] 3. Hirt, G.; Dávalos-Julca, D.H. Tailored profilesmade of tailor rolled strips by roll forming–part 1 of 2. SteelRes. Int.2012,83, 100–105. [CrossRef] 4. Weisheit,A.;Backes,G.;Gasser,A.;Wissenbach,K.;Poprawe,R.Powder injection: Thekeytoreconditioning andgeneratingcomponentsusing lasercladding.Geoforum2001,60, 53–61. 5. Kaierle,S.;Barroi,A.;Noelke,C.;Hermsdorf, J.;Overmeyer,L.;Haferkamp,H.ReviewonLaserDeposition Welding: FromMicro toMacro.Phys. Procedia2012,39, 336–345. [CrossRef] 143