Added Value in SLM Parts Additive World Conference 2016 March 22 nd, 2016 Eindhoven, Netherlands Philipp Stoll inspire AG icams Sankt Gallen, Switzerland
Agenda 1. Who is inspire? 2. Introduction & Motivation 3. Add value to SLM parts different approaches 4. Conclusion & Outlook 2
1. Who is inspire? Competence centre for the Swiss Industry regarding production technique and tooling. Founded on an initiative of ETH-Zürich and machine building industry. Approved as ETH-research annex institute (non-profit foundation). ETH inspire Industry SME Universities of applied science Basic R&D Application driven R&D Technology Development Product development 3
1. Who is inspire? ETH Zurich Empa St.Gallen, icams Technopark Zurich, Headquaters Fields of activity / institutes - Iwf-processes: Grinding, Cutting, EDM, - Iwf-machines: Machine Tools, Simulation, Analysis, Improvements - Iwf-micromachining: Laser- & Microfabrication - icams: Additive Manufacturing (SLS, SLM) - Ipdz: Construction & Design - Ics: Composite-Structures - Icmi: Material integrity - Ifa: Automation, Optimisation, Mechatronic - Ivp: Virtual production / Forming technology 4
1. Who is inspire? Organisation inspire since 01.06.2015 icams A.Spierings/M.Schmid strategic partnership Joint-Venture www.irpd.ch To inspire IRPD AG is a preferred cooperation partner but not an exclusive one! 5
1. inspire icams R&D-focus of SLM group Materials Powder characterization & requirements New materials Hybride materials Alloys for AM Material characterization Microstructure Mechanical properties AM-Processes Processing windows for materials SLM- / SLS- process simulation Residual stresses Process effects Process productivity Applications Lightweight structures Structurally optimised parts / Topology optimisation Smart parts Production of industrially relevant parts Machine Future AM-machine concepts and components Performance QS for AM Standardisation (ASTM-ISO, VDI) 6
2. Introduction Selective Laser Melting (SLM) Energy Z Y X Coord.-System CAD Modell Slice-process Single Build process Slice-information Scanning optic/mirror Focal point (melting of powder) Part that is built Coating device Unmelted powder Building platform Powder container Process chamber 7
2. Motivation The Future of Additive Manufacturing (AM) Parts containing ADDED VALUE Source: Wohler`s Report 2014 8
2. Motivation Added value in SLM parts is essential Reason AM / SLM is today and still for quite some time more expensive compared to conventional manufacturing (lower productivity, energy intensive processes, ) we need an «added value» in the part in order to justify AM 9
3. Add value to SLM parts Added Value in SLM Parts Geometry / Design SLM Process Manufacturing Strategies 10
3. Added value geometry / design Complexity for free Redesign for Additive Manufacturing 11
3. Added value geometry / design Design for Additive Manufacturing Key aspect for using AM! Complex geometries Conformal cooling Bionic structures Lattice structures 12
3. Added value geometry / design Parts designed towards their functional purposes Conventional: TU Hamburg-Harburg, FST Integrated design Additive design: TU Hamburg-Harburg, ilas Reduce number of parts in an assembly Reduce assembling costs Reduce logistic efforts & storage costs Reduce risk (part quality, supplier, ) 16 pieces 1 piece Gibson, Rosen, Stucker (2010), Additive Manufacturing Technologies Rapid Prototyping to Direct Digital Manufacturing 13
Relative part density [%] 3. Added value SLM process Porous structures relative part density E = P Laser v scan h t E= 66.3 J/mm 3 = 99.48 % E= 79.6 J/mm 3 = 99.78 % E= 116.0 J/mm 3 = 99.82 % E= 58.0 J/mm 3 = 98.78 % 1 0.995 0.99 0.985 0.98 E= 132.6 J/mm 3 = 99.86 % E= 49.7 J/mm 3 = 96.57 % 0.975 0.97 0.965 Hatch 90µm Hatch 105µm 0.96 0 50 100 150 200 Volume energy density [J/mm 3 ] 14
3. Added value SLM process Porous structures h < estimated meltpool diameter 25 mm h > estimated meltpool diameter Hatch ratio > 1 v Scan = low E = 30.3 J mm 3 (applied to total area) Hatch ratio > 1 v Scan = medium E = 20.2 J mm 3 (applied to total area) Hatch ratio > 1 v Scan = high E = 15.2 J mm 3 (applied to total area) Porosity = 37.4 % *) Porosity = 55.4 % *) Porosity = 58.4 % *) y x *) black & white analysis of layer that is shown 15
3. Added value SLM process h > estimated meltpool diameter «defined» geometry according to process control 2 CAD-model files required Manufacturing of micro channels in building direction (2) (1) Micro channels: oil - pressure: 0.4 bar - time: 391 sec. - quantity: 15 ml 16
3. Added value SLM process h > estimated meltpool diameter «defined» geometry according to process control 2 CAD-model files required Manufacturing of lamellar structures xy-plane Building direction 17
3. Added value SLM process h > estimated meltpool diameter Manufacturing of lamellar structures Pressing lubricant through lamellar structure Building direction Lamellar, porous structures Lubrication supply 18
3. Added value SLM process h > estimated meltpool diameter Machining of lamellar structures is a critical issue as built Building direction grinded Different levels of machining quality Result of mechanical machining process is not predictable yet! 19
3. Added value manufacturing strategy Integration of external components Energy Z Y X Coord.-System CAD Modell Slice-process Single Build process Slice-information Temperature sensors 20
3. Added value manufacturing strategy Integration of a thermoelement Cavity for sensor integration 21
Temperature [ C] 3. Added value manufacturing strategy Temperature measurement - furnace Temperature [ C] Temperature [ C] 2 K Time [s] Time [s] = 0.6 K Integrated sensor External reference measurement = 0.3 K = 0.4 K = 0.5 K Time [s] 22
Temperature [ C] Temperature [ C] Temperature [ C] 3. Added value manufacturing strategy Temperature measurement blow-dryer Time [s] 20 K Time [s] 10 K Time [s] 23
3. Added value manufacturing strategy Summary: temperature measurement Uniform heating (spacially & in time; furnace) Difference between integrated thermoelement and external reference measurement of less than 2 K In steady state: differences in measurement of just 0.5 K Local heat input strongly varying in time (manually moved blow-dryer) Up to 20 K difference between the two measurements Conclusion: Sensor is able to display relatively slow changes in temperature very well Sensor doesn t show a big delay at start of the measurement Rapid changes in temperature (movement of blow-dryer) cannot be displayed 1:1 this is not the purpose of the embedded sensor Very promising result to display temperature evolvement in parts that are heated up in a moderate way e.g. tools in sheet metal forming 24
4. Conclusion & Outlook Proof of concept has been shown for fluid transportation through porous SLM manufactured structures Proof of concept has been shown for integration of thermoelements encouraging results! Deepen the research on embedding sensors Extend the work to embedding of actuators Shape Memory Alloys (SMA) Piezo Actuators We think there are other types of sensors/actuators to be embedded think about it & don t hesitate to get in contact with us! 25
Thank you for your attention! Philipp Stoll PhD-Student SLM stoll@inspire.ethz.ch +41 71 274 73 27 Building of Empa St.Gallen SLM lab, inspire icams 26