Seminar on 3D Printing of Tooling with case Presentations. Sarig Nachum. Fraunhofer Centre for High Temperature Materials & Design HTL, Fraunhofer ISC

Transcription

1 Seminar on 3D Printing of Tooling with case Presentations 5. April 2017 Sarig Nachum Fraunhofer Centre for High Temperature Materials & Design HTL, Fraunhofer ISC

2 Outline Fraunhofer HTL Motivation of work Binder jetting process Potential of process for mold making Process advantages & disadvantages Material case studies Process development & optimization

3 Fraunhofer HTL

4 Fraunhofer Project Group Recycling and Resource Strategies IWKS Fraunhofer Institute for Silicate Research, Parent Institute ISC Fraunhofer Center for High Temperature Materials and Design HTL Locations: Alzenau, Hanau, Aschaffenburg Locations: Würzburg, Bronnbach Locations: Bayreuth, Würzburg, Münchberg 2 / 5

5 Fraunhofer-Center for High Temperature Materials and Design HTL Standorte HTL Itzehoe Lübeck Bremerhaven Hamburg Oldenburg Bremen Rostock Location Würzburg Hannover Potsdam Berlin Teltow Braunschweig Magdeburg Cottbus Oberhausen Paderborn Hall Dortmund Schkopau e Leipzig Duisburg Kassel Schmallenberg Leuna Dresden St. Augustin Jena Aachen Freiberg Euskirchen Gießen Erfurt Chemnitz Wachtberg Ilmenau Darmstadt Würzburg Bayreuth Erlangen Bronnbach St. Ingbert Kaiserslautern Fürth Nürnberg Saarbrücken Karlsruhe Pfinztal Ettlingen Stuttgart Straubing Freising Freiburg Augsburg Garching München Oberpfaffenhofen Kandern Prien Efringen- Holzkirchen Kirchen Location Bayreuth 4 / 5

6 Fraunhofer-Center for High Temperature Materials and Design HTL Bayreuth Würzburg Münchberg Foundation: Jan Mother institute: Fraunhofer ISC Würzburg Employees: 100 (55 PY) only HTL Lab area: 2000 m² Budget 2016 HTL: 6 Mio Mio. contract research 0.73 Mio. basic funding

7 Working areas of the Center HTL High Temperature Materials Fibers Coatings Composites Ceramics High Temperature Characterization Materials Processes High Temperature Processes Measuring Simulation Optimization High Temperature Components Energy- Propulsion- Heat Technology

8 Assistance S. Klose Center HTL Head: Dr. F. Raether Deputy: Dr. A. Nöth QM R. Herborn Metal Ceramic Composites Simulation Application Center Textile Fiber Ceramics Dr. S. Nachum Development area Dr. G. Seifert Prof. F. Ficker Deputy: A. Luft Ceramics Precursor Ceramics Composite Technolgy Materials Testing Dr. H. Friedrich Deputy: J. Baber Dr. A. Nöth Deputy: A. Rüdinger Dr. J. Schmidt Deputy: C. Eckardt J. Hausherr 3 / 5

9 Motivation of work: Additive Manufacturing

10 How 3D printing will revolutionize industry value chains over time 2014 Deloitte Services LP

11 3D printing: Binder-Jetting Technology

12 Operation steps of the binder jetting process (I) spreading a layer of powder in a powder-bed (II) Jetting 2D-layer with an organic liquid binder (III) partial curing of liquid binder (~50 ºC) (I) spreading powder ExOne s print head (II) jetting binder (III) partial curing M-Flex from ExOne

13 Printing process Further Process Steps Binder curing Removal cured parts dense parts ~45 vol. % porosity Final part Infiltration/sintering preparation of cured parts for infiltration/sintering

14 Technical information technical information large print volume (x,y,z): 25X 40 X 25 cm 3 high resolution: x & y =60µm, z=100µm high speed (z axis): 3-12 mm h -1 Production rate max.: ~1000 cm 3 h -1 complex shapes: diverse shapes in one job Y X 10cm material availability stainless steel alloys (Fe) nickel-based super-alloys (Ni) tungsten (W) tungsten carbide (WC) Hardmetals (WC-Co) Silicon carbide (SiC) Alumina (Al 2 O 3 )

15 Wall thickness A wall thickness as low as 0.1mm is doable

16 Länge der Bohrungen [mm] Channel diameter & length Durchmesser der Bohrungen [mm] channel diameter (mm) 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 50mm 1,0 100mm 0.1mm 1mm channel length (mm) 2,0 5,0 10,0 20,0 50,0 100,0 offene Bohrung geschlossene Bohrung Bohrung mit Draht durchgestochen smallest channel diameter free of powder: 0.4 mm longest channel free of powder: mm

17 Advantages & disadvantages of the binder jetting process advantage of process (I) maintain chemistry & microstructure of powder (II) no thermal management considerations (less variables) (III) no support structures (IV) no residual stress (isotropic properties) (V) no distortion (infiltration) (VI) material flexibility (metal, ceramic, BUT not reactive material!) (VII)high throughput (high print speed) disadvantage of process (I) Preform is ~45 vol.% porous (II) Reduced sinterability printed preform

18 Advantages & disadvantages of the binder jetting process printed preforms solid state sintering sintering (residual porosity) overpressure sintering HIPing (fully dense) metal melt infiltration dense state no shrinkage diverse composites & properties metal printed preforms

19 Potential of process for mold making

20 Types of mold realized by the binder jetting process (I) porous (II) single material (III) composite Type of molds: (I) porous: homogeneous porosity < 40 vol. %, integrated complex cooling channels, transfer of vacuum & heat for forming plastic sheets, (II) single material: integrated complex cooling channels (III) composite: enhancing desired physical properties of mold (thermal conductivity, strength etc.)

21 advantages of 3D printing reduce lead time (new designs or improvement of existing designs) reduce costs (expensive waste material, new tooling) complex parts (complex cooling channels improve mold quality) high production rate (~1000 cm 3 /h) lowering justification threshold (new or optimized tools) reduce labor time (welding or brazing components) disadvantages of 3D printing surface quality (roughness ~50 μm) size limitation (40 X 25 X 25 cm 3 ) diverse materials (powder development) porosity (sintering, infiltration) improvement of surface quality usage of tailored binder powder size distribution (<30 μm) layer size (<100 μm) hand polishing, sand blasting, shot peening electro-polishing Clear coating, electro-plating, powder coat, paint abrasive flow machining, CNC 3D printed mold picture taken from:

22 Wall thickness A wall thickness as low as 0.1mm is doable

23 Länge der Bohrungen [mm] Channel diameter & length Durchmesser der Bohrungen [mm] channel diameter (mm) 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 50mm 1,0 100mm 0.1mm 1mm channel length (mm) 2,0 5,0 10,0 20,0 50,0 100,0 offene Bohrung geschlossene Bohrung Bohrung mit Draht durchgestochen smallest channel diameter free of powder: 0.4 mm longest channel free of powder: mm

24 Advantages & disadvantages of the binder jetting process advantage of process (I) maintain chemistry & microstructure of powder (II) no thermal management considerations (less variables) (III) no support structures (IV) no residual stress (isotropic properties) (V) no distortion (infiltration) (VI) material flexibility (metal, ceramic, BUT not reactive material!) (VII)high throughput (high print speed) disadvantage of process (I) Preform is ~45 vol.% porous (II) Reduced sinterability printed preform

25 Advantages & disadvantages of the binder jetting process printed preforms solid state sintering sintering (residual porosity) overpressure sintering HIPing (fully dense) metal melt infiltration dense state no shrinkage diverse composites & properties metal printed preforms

26 Martensitic stainless steel

27 Preforms printed with martensitic stainless steel powder

28 sintering

29 Martensitic stainless steel sintered in 1350 C as-printed vacuum argon N 2 atmosphere as-printed vacuum argon N 2 open porosity (vol. %)

30 Martensitic stainless steel sintered in N 2 as-printed 1350 C 1370 C 1390 C T max ( C) as-printed open porosity (vol. %)

31 Sintered martensitic stainless steel parts

32 Infiltration

33 Martensitic stainless steel infiltrated with bronze stainless steel preform bronze infiltrated stainless steel

34 microstructure: bronze infiltrated steel steel steel bronze bronze

35 Mechanical properties: steel-bronze composites sintered stainless steel Vickers hardness 2μm bronze infiltrated stainless steel

36 Tungsten Carbide

37 Printing WC powder

38 Microstructure: Co infiltrated WC WC powder microstructure: Co infiltrated WC Co WC

39 Microstructure: Co infiltrated WC WC powder microstructure: Co infiltrated WC Co WC

40 Hardness WC-Co composites Vickers hardness WC-Co composites

41 Alumina

42 Printed Al 2 O 3 preforms Al 2 O 3 preforms Fe infiltrated Al 2 O 3 Wear resistance tools Cu infiltrated Al 2 O 3 High thermal & electrical conductivity Al infiltrated Al 2 O 3 Wear resistance light weight

43 Silicon Carbide

44 SiC preforms

45 Further development

46 Powder optimization

47 Powder characterization size & shape surface & microstructure composition & impurities

48 Powder flowability: characterizations Hall-flowmeter repose angle cohesive strength 37 37

49 Powder optimizations relative density (%) Improve packing density: bi-modal & shape distributions number of taps

50 Powder optimization: flow agents Coating powder with nanoparticles To increase flowability For microstructural benefits flow agent Al 2 O 3

51 Powder optimization: flow agents WC powder Al 2 O 3 powder

52 Binder development

53 Segmentation index viscosity (mps) Particle loaded liquid binder suspensions smaller fraction of rheological additive Time (days) shear rate (s -1 )

54 suspension density porosity Binder development wt. % of solid A B type of printed powder

55 Particle infiltration

56 Phenolic resin infiltration Polymer Infiltration & Pyrolysis (PIP) Preform Phenolic resin with/out particles Vacuum infiltration of resin Pyrolysis in inert atmosphere Polymer transformation to ceramic

57 Powder-bed homogeneity

58 CT scans of printed parts CT Scan analysis determine homogeneity of powder-bed distribution of material, porosity and binder