Page - 147 - in 3D Printing of Metals

Metals 2016,6, 313 2.2.Arrangementof theExperiments Toevaluate the feasibilityandthecontrolparametersof thedesignedexperiment, aSn63Pb37 alloywas involvedinthiswork.Accordingtoactualsituation, thecrucible temperaturewasheated to270 ◦C, the initialdistancebetweenthemicro-coatingnozzleandthesubstratewasset to1.6mm, thesubstrate temperaturewasset to90 ◦C,andtheargonmassflowmeterpressurewasset to100KPa. Single-layersinglepass (SLSP)experimental conditionsareshowninTable1. Table1.Experimental conditionofmicro-coatingmetaladditivemanufacturing(MCMAM). PropertyandParameter Value Coatingheadtemperature 270 ◦C Heatingsubstrate 90 ◦C Argonmassflowmeter 20–70mm3/s Depositionvelocity 9–24mm/s Initialdistance 1.6mm Layer thickness 0.9–2.1mm Coatingnozzle 0.3mm Pressure 100KPa Glovebox Ar(99.999%) (20ppm) Sizeofcopper-cladsubstrate 300mm×200mm×10mm SLSPdeposited length 130mm multilayersinglepassdeposited length 100mm 3.ResultsandDiscussion Asabasicunit, the formingprocessofasingle-trackspecimenshouldbeprimarily investigated. Therearemanyprocessparameters intheMCMAMformingprocess, includingthedepositionvelocity, the flowrate, thedistance from thenozzle to theworkpiece, the heating temperature, the nozzle size, and the heat dissipation conditions, having great impacts on the final forming quality of specimens. Thepresentpaper focusesonthedepositionvelocity, theflowrate,andthe layer thickness; thus,other factorsarekeptconstant. 3.1. PreliminaryExperiments toDetermine theProcessWindowofSLSP In this section, the effect of flow rate and deposition velocity on the formingmorphology is explored. The flow rate varied from 20 to 70 mm3/s, and the deposition velocity varied from9to24mm/s.AccordingtotheparameterspresentedinTable1,asetofpreliminaryexperiments had been conducted. Moreover, the SLSP combination was evaluated according to the surface morphology and the relationship between the process parameters and the formingmorphology ofSLSPwereanalyzed, theresultsofwhichcanbefoundinFigure2. 147