Laser Beam Welding in Vacuum - NRW.INVEST
Transcript of Laser Beam Welding in Vacuum - NRW.INVEST
Laser Beam Welding in VacuumIncrease in Quality and Productivity Dr. Christian [email protected]
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- Solution provider for laser beam welding in vacuum- Founded 04/2018 - Spin-Off of FH Aachen University of Applied Science - Location TPH 1 in Herzogenrath- Customer relations worldwide- Different certification
LaVa-X GmbH
ISO 3834
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LaVa-X GmbH – Business Model
YOUR SOLUTION PROVIDER FOR WELDING CHALLENGES!
EquipmentJob-ShopConsulting
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“LaVa-Effect”
Ø Change of Melting Point < 1 K Ø Change of Evaporation Point approx. 1000 K
0
500
1000
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3000
0,001 0,01 0,1 1 10 100 1000
Tem
pera
ture
[°C]
Pressure [mbar]
Boiling Temperature over Pressure
Cu [°C] Al [°C] Fe [°C]
Evaporation PointMelting Point
- Lower temperature leads to thinner melt pool around keyhole- Increased Keyhole stability (at lower welding speed)
ΔT =𝑇! ∗ Δ𝑉 ∗ ∆𝑝
𝐻!Clausius Clapeyron
(simplified)
𝑇! = Melting Point𝐻! = 𝑀𝑒𝑙𝑡𝑖𝑛𝑔 𝐸𝑛𝑡ℎ𝑎𝑙𝑝𝑦Δ𝑉 = 𝑉𝑜𝑙𝑢𝑚𝑒 𝑐ℎ𝑎𝑛𝑔𝑒 𝑑𝑢𝑟𝑖𝑛𝑔 𝑚𝑒𝑙𝑡𝑖𝑛𝑔
Minimal volume change (~ 3-5%)∆𝑝 < 1000 𝑚𝑏𝑎𝑟
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LaVa-Welding
Increase of qualityNo pores or cracks in weld seams evenin alloys difficult to weld.
Increase of ProductivityIncrease of penetration depth or reduction of laser power. No distortion.
Avoidance of spattersNo adherend spatters, avoidance ofvapour deposition and oxidation
Economic and ecologicUse of low power laser sources. No compressed air and less shielding gas.
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Exemplary Fields of Application LaVa-Welding
Sensor Industry- No pores & component contamination
- Heat input reduced by up to 60 % / 500 W ≙ 3 mm depth- Less welding distortion & spatter
Medical Industry- Highest weld quality & a 100 % protection against oxidation
- Titanium, nitinol, gold, tantalum and chrome-nickel steel - Good automation capability and high reproducibility
Automotive- Additive manufactured components
- Difficult weldable alloys- Material combinations
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System Technology - LaVaCELL 450Laser & Optics- Fiber & Disc Laser- 40 µm Spot (500 W)- 55 µm Spot (2000 W)- 150 µm Spot (2000 W)- 450 µm Spot (8000 W)- 375 µm Spot (12000 W)
LaVaCELL450
Y-Axis Turntable
DN250
DN250
Vacuum Chamber
Rotation Axis
X-Shift Cover Plate
Counterholder
X-Shift
Welding Head Typ R Welding Head Typ T
Modular System
- 20 µm – 40 mm
40 mm
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- LaVa-Welding of Bipolar Plates- 1.4301 & 1.4760 (Crofer®)- 55 µm Spot (PL=45 W; v=200 mm/s)
Stainless Steel (Example Bipolar Plates)
Overlap Weld
t=75 µm
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- 85 µm Spot (PL=120 W; v=900 mm/s)
Stainless Steel (Example Bipolar Plates)
- Transfer line with- pressure stage system- à NO secondary
time for evacuation
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Challenges laser welding of AlPhysics
[1] G. Schulze, Die Metallurgie des Schweißens, Berlin: Springer Verlag, 2007
Temperatur [K]
Cracks
Temperature [K]933 2743
100
0,01
Pores
0 100 200 300 400 500
Cu [°C]
Al [°C]
Fe [°C]
Thermal Conductivity [W/mK]
Thermal Conductivity
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Challenges laser welding of Al
Atmosphere
LaVa
Weld pool + 33%
Lower difference stabilized weld pool.Less Oxygen leads to a better outgas of pores.
896,8
1809,8
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Al [°C]
Tem
pera
ture
[°C]
Difference between Boiling- and Melting Temperature
LaVa Atmosphere
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- LaVa-Welding of Flat Cable- EN AW 1050 (99,5%)- 150 µm Spot (PL=1800 W; v=25 mm/s)
Aluminum (Flat Cable) Butt Joint
Topside
Bottom
4 m
m
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Challenges laser welding of CuPhysics
Temperature [K]
Absorption Melting Interval
1400
1300
1200
1100
1000
900
800 0 0,002 0,004 0,006 0,008 0,012
α+Cu2O
α
Gew.-%
K
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60
40
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0
Abso
rptio
n in
%
Wavelength λ in nm100 1030 -1080 10000
15
10
5 Abso
rptio
n in
%
Surface temperature T in K0 1000 2000500 1500
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20
0 100 200 300 400 500
Cu [°C]
Al [°C]
Fe [°C]
Thermal Conductivity [W/mK]
Thermal Conductivity
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Challenges laser welding Cu
Atmosphere
LaVa
Reduced melt pool stabilized Keyhole and increased efficiency
Weld pool + 52% 532,38
1510,38
0200400600800
1000120014001600
Cu [°C]
Tem
pera
ture
[°C]
Difference between Boiling- and Melting Temperature
LaVa Atmosphere
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Copper with IR LASER
Influence beam oscillation with 2000 W
Penetration 250 µm with 350 W
Penetration 6 mm with 6000 W
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- LaVa-Welding of Hairpins- Cu-ETP & Cu-OF -55 µm Spot (PL=2000 W; t=0,12 s)
Copper (Hairpins)
Cu-OF
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- LaVa-Welding of Hairpins- Cu-ETP & Cu-OF -55 µm Spot (PL=2000 W; t=0,12 s)
Copper (Hairpins)
Cu-OFCu-ETP
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Challenges Welding of Mixed MaterialsPhysics Crystal System Intermetallics
FCC
BCC
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1000
2000
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Cu [°C] Al [°C] Fe [°C]
Tem
pera
ture
[°C]
Melting- and Boilingpoint
Boilingpoint Melting Point
0 100 200 300 400 500
Cu [°C]
Al [°C]
Fe [°C]
Thermal Conductivity [W/mK]
Thermal Conductivity
Al-Cu
[2] MSI Eureka
Al2Cu
[2]
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- LaVa-Welding Current Contacts- ETP-Copper with Al 99,5 (EN AW 1050)- 150 µm Spot (PL=600-2000 W; v=25-60 mm/s)
Mixed Materials (Al-Cu)
Overlap Weld
t = 0,2 - 4,0mm
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Al 1,5 mm Al 3,0 mm
Tens
ile S
tren
gth
[N/m
m²]
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Mixed Materials (Al-Cu)
α(Al)
EAl2Cu
Cu
[3] Otten, Welding in the World, DOI 10.1007/s40194-015-0280-x, 2016
Kernel Average Misorientation
Stress peaks at the grain boundaries lead to failure.
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LaVa-Welding Solves Problems
Hugh Potential for large Structures!
New Materials
1mm
500 µm
Reduced Laser Power500 W vs. 2 kW
Stationary Machines
conventional
20m
m
Thick Plate Applications
LaVa
50m
m
[4] Jakobs, Dissertation, 2016
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Comparison of ambient Pressure and Vacuum
PL = 12 kW; vs = 10 mm/s; A = 0,5 mm; F = 200 Hz
Atmosphere Vacuum
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Laser Welding with mobile vacuum
All stationary machines resluts are transferable to mobile vacuum applications!
5 mm
Pene
trat
ion
dept
h20
mm
P L=
6 kW
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Edge Misalignment and Gap Bridgin AbilityWith Filler-Wire
Gap Width 1 mmWithout Filler-WireGap Width 1 mm
Edge Misalignment0 mm
Edge Misalignment2 mm
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- LaVa-X is a Solution Provider for Welding Challenges
- LaVa-Welding is a Suitable Technique for varies applications
- Steel: LaVa-welds can be conducted up to 900 mm/s
- Aluminum: Pores, cracks and heat-input can be reduced with LaVa
- Copper: Spatters can be reduced and penetration depth can be increased
- Al-Cu Mixed Joints: Stable Keyhole leads to reproducible temperature-time-gradient
- Thick Plate Applications: Significant Increase of Penetration Depth and Quality
Conclusion
Please Contact me for further questions!ContactDr. Christian Otten02407 95389 [email protected]