Page - 134 - in 3D Printing of Metals

Metals 2017,7, 113 2. In thesecondcase, laser cladding isapplied to thesemi-finishedproductbefore forming: as formingoperation,holeflangingisconsidered. Sinceflangingmayreducethesheet thickness, thickeningbycladdingmayallowthedesiredminimumsheetthicknesstoremain,e.g., forcutting a threadinto theflange,asshowninFigure1. In the following,bothroutesaredescribed individually. 2.3.Demonstrator I:StiffnessManagementofPre-FormedPart 2.3.1.DemonstratorGeometryandOptimizationTask An idealizedsuspensiondomemadeof thealuminumwroughtalloyENAW6082 isusedas a demonstrator (Figure 4) to analyze the possibility of stiffnessmanagement by local, additively manufactured reinforcements. The basic part shown inFigure 4a is a cylindrical cupwith awall thicknessof1mmandacentralhole in the topface. Inareal suspensiondome, thesuspensionwould befastenedto thecentralhole,whichwouldtransmit thesuspensionforces into thecarbodystructure. Figure4.Demonstratorgeometryasbasisvariant (a) andpossiblealternativeswith increasedstiffness: patchworkblank(b) andtailored lasercladding(c). Basedonthegivencomponentgeometry,welookforpossibilities to increase thepart stiffness under the central loadusingaminimumofaddedmaterial. Suchan increase in stiffness couldbe required inavariantwithaheavierengineor,alternatively, simply tosaveweight. Thus,we lookfora thicknessdistributionthatminimizes thedeflectionof theholeedgeanddesignitusingpatchwork blanks,Figure4b,andusingalaser-claddedreinforcement,Figure4c. Thetotaladdedmaterialvolume isequal inbothcases. Thecasestudyshouldshowtheadvantagesof thestiffness-optimizedvariant comparedto thebasicvariantandthepatchworkblank. Todefinethegeometryof the lasercladding,asizingoptimizationof thebasicvariantwascarried outusingAbaqus/TOSCAtodetermineanoptimalnon-linear thicknessdistributionresulting ina 134