1Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Industrial Workshop Programme
13:30 WelcomeDominiek Reynaerts
(KULeuven)
13:35 - 13:45Introduction by EC project officer of the European project Hi-Micro
Erastos Filos
(European Commission)
13:45 - 14:00 Introduction Hi Micro and Change2Micro
Jun Qian
(KULeuven) |
Hilde Krikor
(SIRRIS)
14:00 - 14:30High precision technologies for micro manufacturing
Jun Qian (KULeuven) |
Henning Zeidler (TUChemnitz)
14:30 - 15:00 Change2microHilde Krikor
(SIRRIS)
15:00 - 15:30Micro-machining, moulding and printing solutions for polymers at SIRRIS SMALL-Lab
Denis Vandormael | Laurent Seronveaux (SIRRIS)
15:30 - 15:45 Break
15:45 - 16:15 Simulation of precision micro injection mouldingGuido Tosello
(DTU)
16:15 - 16:45Enabling AM & CT technologies for micro injection moulding
Wouter Vanderauwera
(3DS- Layerwise) |
Andrew Ramsey
(NIKON)
16:45 - 17:15Micro injection moulding with integrated in-process quality control
Björn Dormann
(DESMA)
17.15 – 19:00 Closing remarks and networking reception (visit to KULeuven facilities)
© EU-FP7 HI-MICRO
Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
High precision technologies for
micro manufacturing
Jun Qian, KU Leuven
Henning Zeidler (TUChemnitz)
© EU-FP7 HI-MICRO
Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
KULeuven
Micro-EDM and wire-EDM
4Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
3D MICRO-EDM MILLING
4
3D Micro-EDM machine with access to certain parameters
Layer by layer 3D milling
5Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
CHALLENGES IN MICRO-EDM MILLING
• Non-linear process (material
removal vs sparking energy)
• Unstable process (stochastic
process)
• Low material removal rate
• Tool wear compensation
– Tool wear measurement/prediction
– Tool wear compensation &
implementation
6Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
LINEAR TOOL WEAR COMPENSATION
WorkpieceTool
Without wear compensation With wear compensationIn-process variable tan δ
PULSE MONITORING/COUNTING BASED
LINEAR WEAR COMPENSATION
Pulse no. = 1208
𝑾𝒆 = 𝟎
𝒕𝒆
𝒖𝒆 𝒕 ∙ 𝒊𝒆(𝒕) ∙ 𝒅𝒕Spark energy:
Pulse monitoring
Processed current waveforms
8Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
MICRO INJECTION MOLDING OF 3D PARTS
Wire-EDM on Cut 300mS
9Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
MICRO-EDM MILLING
Position measured value drawing value difference
b1-x -0.002 0 0.002
b1-y 0.002 0 -0.002
radi B1 0.437 0.39 -0.047
b2-x -2.214 -2.17 0.044
b2-y 2.981 2.98 -0.001
Radi B2 1.382 1.37 -0.012
b3-x -3.396 -3.32 0.076
b3-y 7.231 7.32 0.089
Radi B3 0.166 0.13 -0.036
b4-x -6.938 -6.86 0.078
b4-y 8.175 8.26 0.085
Radi B4 0.981 0.97 -0.011
C5-x -6.987 -6.91 0.077
C5-y 7.532 7.61 0.078
Radius +/- 22 micron(10 micron required)
© EU-FP7 HI-MICRO
Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
TUChemnitz
PECM, Jet-ECM, Multiphysics Simulation
11Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Principle of anodic metal dissolution:
Electrical voltage source: Workpiece = Anode (+), Tool = Cathode (-)
Current transport through an electrically conductive fluid (electrolyte)
Anode: donation of electrons generation of metallic ions pass into the electrolyte
removal of material
Electrolyte: precipitation reactions, enable a filtration of removal products
Cathode: no removal
Possibility of oxidation at the anode and
reduction at the cathode
Application areas:
Automotive- and aviation engine design
Tool making
Micro machining
ELECTROCHEMICAL MACHINING WITH EXTERNAL
VOLTAGE SOURCE
Scheme of anodic metal dissolution
Hydrous electrolyte
e.g.: NaNO3 - Dissolution
Kathodic
reduction
Anodic metal
dissolution
2H2O + 2e-
H2↑ + 2OH-
NO3 + H2O + 2e-
NO2- + 2OH-
Following reactions, e.g.:
Men+ + nOH- → Me(OH)n ↓
Me → Men+ + n e-
Anode Cathode
12Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Process: No mechanical contact between tool and workpiece No process inherent tool wear Low processing temperature No burring Process parallelisation only limited by current supply, not by
removal mechanism
Shape: Difficult to access geometries (undercuts) Complex shapes in hollow, geared or slotted profile parts Thin-walled, fragile and complex workpieces
Material Super alloys and powder metallurgic steels No change of microstructure in the workpiece
potential technique for machining of complex parts,
using additive manufactured alloys
ADVANTAGES OF ELECTROCHEMICAL MACHINING
Selective Jet-ECM removal
PECM removal
13Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Principle:
Localisation of electrical current density in
a closed electrolytic free jet
Shaping by movement of the nozzle and control ofelectric current
Characteristics:
Electrical current density up to 2000 A/cm² (DC)
Feed up to 150 mm/min
Very good electrolyte flushing (vJet > 70 km/h)
High geometric flexibility
Variants: Milling, cutting, drilling, turning
Applications:
Microfluidics, Miniaturisation of parts
Creating microstructured surfaces
Cutting of foils (also material selective)
JET-ECM –
ELECTROCHEMICAL MACHINING WITH ELECTROLYTE JET
Schematic setup
Jet-ECM ablation progress
electrolyte supply
nozzle
working gap
workpiece
closed
free jet
_
+
15Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Video of Jet-EC cutting metal-plastic laminates
for photovoltaic applications
Selective removal of an Aluminium coating from a Polyester-substrate,Trench width: 1 mmDepth: 50 µmNozzle speed: 500 µm/s
Jet-EC drilling of selective laser
melted 18Ni-300 and AlSi10Mg
Bore-Ø: (170…300) µmDepth: (5…130) µm depending on material and machining time
JET-ECM EXAMPLES
16Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
SEM-Image of a micro mixer in stainless steel 1.4541 (channel width: 200 µm, depth: 60 µm)
Measurement results of Jet-EC milled micro structures for measurement calibration
Video of Jet-EC milling
Jet-EC milling of a micro reactor in stainless steel nozzle diameter: 100 µmvf = 30 mm/min
JET-ECM EXAMPLES
17Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Stainless steel 1.4301
SEM-images of machined areas
Video of Jet-EC turning
Jet-EC turning, Machining sequence: 4, 5, 6
JET-ECM EXAMPLES
18Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Average grain size: g = 1 µm
Voltage: U = 20 V
Nozzle speed:
1. cycle: v1 = 200 µm/s
2. cycle: v2 = 1000 µm/s
Machining is possible when using
combined electrolytes
SEM-image of Jet-EC milled trenches
Video of Jet-EC milling of WC-Co6 cemented carbide
JET-ECM EXAMPLES
v=
10
00
µm
/s
v=
20
0 µ
m/s
19Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Principle:
Anodic metal dissolution using pulsed current
Localisation of removal area by minimising working
gap
Often combination with oscillating working gap
Advantages:
Roughing/Finishing in one machining
step possible
High reproduction accuracy
Surface quality up to Ra = 0,03 μm
Applications:
Tool- and mould making, dies,
punches etc.
Microsystem technology
PECM – PULSED ELECTROCHEMICAL MACHINING
Principle of Precise Electrochemical Machining
s ,I
t
s(t)
I II III
Ca
tho
de
Ca
tho
de
Ele
crto
lyte
Ele
crto
lyte
Ele
ctro
lyte
Anode
Ca
tho
de
Ca
tho
de
Ele
ctro
lyte
Anode
I(t) I(t)∆s
∆z
IV
t1 t2 t3 t4
PEM-Center 8000, PEMTec
20Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Electrolyte processing:
Conductivity
Temperature
pH-Values
Kinematics:
Feed motion
Oscillation
Control:
Control software and hardware
Operation
Generator:
Process current
Process voltage
PECM – MACHINE TOOL SETUP
Schematic View of a PECM machine tool
Degassing of oxygen and
hydrogenPulsed current
Electrolyte
Sensor system and control
21Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Machining of micro-structures
PECM – EXAMPLES
SEM image of the micro-milled cathode
SEM image of PECM machining result:
cavity for injection molding, feed rate: 35 µm/min
tool holder
flushing chamber
work piece
work piece holder
Photograph of the PECM tool setup
22Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
PECM – EXAMPLES
Blank (left) and PECMed forming tool (right), feed speed 0.2 mm/min, HSS, Ra 0.18 µm
Machining of micro-structures with high aspect
ratio
Structure for brain imlants;4000 spikes per cm²,height: 500 µm, Ø 70 µm,machining time: 20 min
Cavity in stainless steel1.4301,depth 1.8 mm, width 0.2 mm, aspect ratio: 9
Surface roughness detection on forming tool
23Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Multitude of physical parameters:
Experimental parameters
Data acquisition
Implementation
Coupling
Approaches:
Sequential simulation of parameters
Definition of target values, examination of
relevance of parameters
Reduction to simulation of relevant
parameters
PROCESS DESIGN BY MULTIPHYSICS SIMULATIONS
Influence and of physical parameters Einflussgrößen on FEM-simulation of electrochemical prozesses
24Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
FEM-Simulation of PECM
Simulation of the removal process
Feed speed 30µm/min
Sequiential simulation of the removal
and the feed of the cathode
Increasing precision and decreasing
roundings by using an undercut and
by a side insulated on the cathode
PROCESS DESIGN BY MULTIPHYSICS SIMULATIONS
Geometrical model for Jet-ECM simulation withdynamic electrolyte jet
FEM-simulation of the PECM removal
FEM-simulation of the PECM removal with insulatedelectrode (left) and with undercut electrode (right)
25Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Challenges in the beginning of the Hi-Micro project:
Unknown process parameters for electrochemical machining of additive manufactured materials
Missing knowledge about removal behaviour of AMed steel 18Ni-300 and aluminium AlSi10Mg
No knowledge about electrode design for PECM fabrication of micro injection moulds
CHALLENGES
Jet-ECM machinability studyon SLMed 18Ni-300
Jet-ECM machinability studyon SLMed AlSi10Mg
26Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
Outcome of the Hi-Micro project in terms of ECM:
Machinability studies for the determination of process parameters for PECM and Jet-ECM of additive
manufactured materials were carried out
Electrochemical removal of additive manufactured and molten metallurgical steel were analysed and compared to each other paths of the SLM process are revealed
Several experiments and FEM-simulations of PECM for manufacturing of IM cavities were performed increasing accuracy due to undercut and insulated cathode was analysed
Novel tool setup for PECM of injection molding cavities was designed and realised
OUTCOME
27Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium
THANK YOU!
28Revolutionary Technologies in Micro Injection Moulding
30 September 2015, Leuven, Belgium