3D SCREEN PRINTING MASS PRODUCTION OF METALS AND CERAMICS T. Studnitzky
Fraunhofer-Gesellschaft Itzehoe Lübeck Rostock Bremerhaven Bremen Oberhausen Dortmund Duisburg Schmallenberg St. Augustin Aachen Euskirchen Hannover Braunschweig Darmstadt Würzburg Erlangen St. Ingbert Kaiserslautern Fürth Nürnberg Saarbrücken Karlsruhe Pfinztal Stuttgart Freising Freiburg München Potsdam Berlin Teltow Magdeburg Cottbus Halle Schkopau Leipzig Dresden Jena Chemnitz Ilmenau 67 Fraunhofer institutes and independent research units in Germany 23.000 employees 12 institutes or branches in Dresden 4 of these at the Fraunhofer Institute Center Dresden Efringen- Kirchen Holzkirchen
Fraunhofer IFAM: Branch Lab Dresden Permanent staff 62 Student employees 28 Budget 6.8 Mio. Industry 32 % Projects 56 % Public funding 12 % Investments 0.8 Mio. Area 2470 m 2 Director: Prof. Dr.-Ing. Bernd Kieback (Budget 2014)
Metal Additive Manufacturing @ Fraunhofer IFAM Laser Beam Melting (LBM) [HB] Electron Beam Melting (EBM) [DD] 3D Metal Printing - Binder Jetting approach (3DP) [HB] 3D Metal Printing - S creen Printing approach (3DMP) [DD] 3D Metal Printing - Binder Jetting approach (3DP) [HB]
3D with screen printing? Additive manufacturing process, patented 1993 2008 first 3D-Screen Printing facility, first machine in R&D worldwide 2014 working group 3D Metal Printing with six scientists and one technician 2014 new groundbreaking machine specially designed for 3D screen printing 10 mm
Process scheme Flooding, Printing & Hardening Screen Partners: PVF (Hall 6, Booth B39) Koenen Solar (Hall 3, Booth 355) Lift screen Optional: screen change Optional: Different material Sintering
3D stencil printing new option Stencil instead of screen No Moiré effect Closed frames possible with holding grid M-TeCK stencil -> Christian Koenen GmbH (Hall A3, Booth 355) Possible higher layers and larger bridging Source: Christian Koenen GmbH M-TeCK stencil Printed options Printed structures
Achievable geometrical details (screen printing) Constant wall thickness (minimal 60 µm) Maximal height of several cm Constant cell size Possible bending in the green state Properties of print: Wall thickness: 100 µm Wall height: 1.5 mm
Achievable geometrical details (screen printing) Feature: Bridging up to 1 mm Undercuts Hollow structures and channels without powder removal or supporting structures Complex inner structures possible 20 mm Sieb 3 100 µm Sieb 2 Sieb 1
Achievable geometrical details (stencil printing) Layer thickness > 300 500 µm Bridging > 2-3 mm Resolution in the range of the layer height Much higher building rate compared to screen printing M-TeCK stencil Printed structures
3D screen printing - materials So far: Metals (based on Fe, Cu, Ti, W, La, Mo, Al, Ta, ) Ceramics? Materials Combinations? Copper, steel and MoSi2 Gas atomized copper
3D screen printing Ceramics Cooperation with Fraunhofer IKTS Water based slurry based on metal systems Printed height: ~ 2 mm, 150 200 µm wall thickness Excellent green strength, no warpage 70 mm 70 mm 6 mm Al 2 O 3 SiC Green part
3D screen printing Multimaterial (adjacent structures) Two screens with different design used Two materials: Steel / Ceramic Sreen change after 5 layers each Printing of adjacent structures possible 10 mm 190 µm Process scheme Printed structures Printed structures
Ceramic 3D screen printing Multimaterial (sandwich structures) Same screen different materials Two materials: Steel / Ceramic Starting with pure ceramic slurry, adding metal slurry during printing Steel Sintered graded structure
Features of the 2 nd generation printing machine at IFAM Two printing tables printing area 300 mm x 300 mm Closed chamber climate control water free pastes possible All printing parameters independently adjustable UV hardening facility Process control taken over from industrial production lines first step towards industrial production machine ASYS / EKRA -> Hall 3, booth 277
3D-Screen Printing Applications Cooling Systems Fuel cell Electric components Implants Heat exchanger Filter µ-reactor Sealings Micromechanics
Bipolor plate fuel cell Integrated channels Goal: Reduction of costs, size and weight structure sizes < 100 µm 10 mm
Example: Micro cooling systems Design of optimized structures (COMSOL) Different CAD models transferred onto one screen
Example: Microparts Special tube for electrical application in cooperation with industry Complex part printed with five screens ~3500 parts printed at the same time on 1 st generation lab machine +700.000 parts per year possible on 1 st generation lab machine
3D screen printing - concepts for mass production 2 nd generation lab machine: decoupling of printing and curing 1.500.000 parts / year Table size 300 x 300 mm² Possible production machine: 1 printing area / 5 substrate tables 7.000.000 parts / year Table size 400 x 600 mm² Possible production line: 4 printing areas / 12 substrate tables simplified printing of complex parts
Economical aspects Technique Built rate Resolution Powder size Tools? [cm 3 / h] [µm] [µm] 3D-Screen Printing (Lab machine IFAM) 3D-Stencil Printing (Lab machine IFAM) Screen / stencil Printing (10 table mass production) 80-200 80-150 < 15 - < 50 Screen 200-600 200-500 < 50 Stencil >> 1000 100 < 15 - < 50 Screen / Stencil SLM / EBM 50-100 300 > 45 -- FDM 50 400 -- --
Economical aspects Calculation (Screen Printing): 316 L Printing area 200 x 300 mm Screen usage 5000 prints (solar industry 10000-100000) 90 % good parts Including: Personnel costs Depreciation Heat treatment
Costs per part [ ] Parts per year Study: µ-heat exchanger Einfluss der Siebfläche auf die Kosten pro Bauteil (2x3 cm) 0,8 Technikumanlage Lab machine IFAM am IFAM 7.000.000 Kosten/Teil [ /Teil] 0,7 0,6 0,5 0,4 0,3 0,2 Einschichtbetrieb, Ein-Tischanlage Schichthöhe pro Lage: 15µm Trocknungszeit pro Lage: 20s Bauteilhöhe: 1mm 6.000.000 5.000.000 4.000.000 3.000.000 2.000.000 Teile pro Jahr 0,1 ~400.000 Bauteile Parts / year pro Jahr 1.000.000 0,0 0,0 0,2 0,4 0,6 0,8 effektive Siebgröße printing [m²] area [m 2 ] 0
Economical aspects
Process chain: From powder to part Partner R&D: Fraunhofer IFAM 3D-Printing machines : EKRA / ASYS Screen / Stencil supplier: Koenen or PVF Powder: Depending on material Furnaces: Different, for e.g. MUT If necessary: Part manufacturer, in negotitian
Economical considerations - take home messages 2D screen printing is an established industrial process process control strategies can be transferred to 3D screen printing Productivity scales inversely with part volume Many different parts or part variations can be made on just one screen Parts that require many screens should be avoided or broken up into simplified geometries otherwise tooling cost goes up, time for screen adjustment goes up Printing directly onto sinter substrate possible easy handling of large numbers of small parts Low wear of printing screens. Screens are inexpensive, several suppliers exist Use of commercially available PIM powders recommended powder cost is known
3D-Screen Printing Quelle: Siebdruckversand Cavities / Channels possible 3D-free form difficult Multicomponent parts Little tooling cost Mass production possible High materials variety Medium surface quality Finishing, if needed Design Tool Manufacturing Postprocessing Beam assisted Additive Manufacturing of metal parts (SLM, EBM) Quelle: FhG IFAM Quelle: Argen No cavities High freedom of design Supporting structures needed No tools needed Limited part numbers Poor surface quality Limited materials variety Removal supporting structure Surface finishing needed Additional heat treatment (SL
3D-Screen Printing Quelle: Siebdruckversand Cavities / Channels possible 3D-free form difficult Multicomponent parts Little tooling cost Mass production possible High materials variety Medium surface quality Finishing, if needed Design Tool Manufacturing Postprocessing Metal Injection Moulding (MIM) Quelle: Indo-MIM / Wittmann Battenfeld Quelle: Arburg Quelle: EC Tech Free outer contour Inner contours limited No cavities High tooling cost Mass production possible High surface quality Typically no finishing needed
Where does 3D screen printing fit in?
Summary 3D screen printing offers new possibilities in product design Possible structure size 60 µm Bridging possible without supporting structure 3D screen printing is suitable for mass production Free choice of material Metals, ceramics, glass Material combinations possible Multilayers Sandwich structures (In printing direction) Adjacent structures (Perpendicular to printing direction) Graded structures