Seite - 139 - in 3D Printing of Metals

Metals 2017,7, 113 3.1.3. StiffnessPropertiesof theReinforcedParts Figure11showstheresultsobtainedbytesting thebasicvariantandtheoptimizeddesignwhich containsa thickenedarea in theradiusregion. In thiscase,withsixpercentaddedmass,astiffness increaseof95%wasobtained. This ismore thanthestiffness increaseobtainedwithapatchworkblank ofconstant thickness. Figure12bshowsacomparisontoapatchworkblankthatusesapatchof the samemassas theproducedcladding. Thechosendesignstilloutperformsthepatchworkblankbut fallsbehind thepossibilitiesofferedbysizingoptimization,Figure12c. This solution increases the stiffnessby163%withonly4.7%addedmass,butwillprobably leadtodistortionof thecomponent. Figure11. (a)Originalpartandpartwith local reinforcement; (b)Resultsof static testing. Figure12. Increase in stiffness andweight for threedifferent reinforcements. (a) Patchworkblank; (b)Tailored lasercladding,pareto-optimum; (c)Tailored lasercladding, sizingoptimization. 3.2. Results forDemonstrator II—Hole-FlangingofTailoredLaser-CladdedBlanks 3.2.1. LaserCladdingStrategies Figure13showstheresultsof the threedifferentcladdingstrategies, revealing that strategywith thespiralpathof the laserbeam(Figure13c)yields thecladdingwiththemostappropriatesurface. Strategieswith straight pathwithparallel offset of the laser beam (Figure 13a,b) didnot allow to producecladdingswithoutdefects in thestartandendpositions. 139