diode laser systems for materials processing applications gary broadhead gary broadhead
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Diode laser systems for materialsDiode laser systems for materialsprocessing applicationsprocessing applications
Introduction to diode lasers
State-of-the-art high power diode lasers
Gary Broadhead Gary Broadhead –– Laser Lines LtdLaser Lines Ltd
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Applications
Conclusion
Laser Lines Ltd
Diode Laser Diode Laser -- Single Emitters and BarsSingle Emitters and Bars
A high power diode laser system comprises a number of individual semiconductor laser devices (usually based on GaAs wafers) whose beams are optically combined to achieve the required total power. These individual elements are either “Single Emitter” or “Bar” devices. A bar is a monolithic linear array of devices fabricated on the wafer. The wavelength of laser diode systems is usually 9xx nm (915/940/980)
Single Emitter Bar
Power 10 W 150 W
Efficiency 50 % 30 – 40 %
Cooling Passive Passive or active
MTBF > 500,000 hours Up to 80,000hours
Passively cooled bar (above)
2Laser Lines Ltd
hours
Single Emitter
Actively cooled bars
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Diode Laser Diode Laser -- Single Emitters and BarsSingle Emitters and Bars
Typical fibre-coupled single emitter based sub-module containing 10 to 16 devices inside. Output power up to 120 Watts at 940/980nm. Air cooled.
Size approx 12cm x 5cm x 2.5cm
Multiple SE modules can be readily combined to provide laser powers of around 1kW.
Typical bar based sub-module (“Stack”) in this case comprising 6 bars. A 10 bar stack could deliver 1.5kW of laser power.
3Laser Lines Ltd
Size approx 5cm x 5cm x 2cm
Multiple stacks can be combined to provide laser powers in excess of 12kW.
Modular Product
Coupling methods: wavelength and polarisation
Basics: Laser Beam SourceBasics: Laser Beam Source
Polarisation couplingEasy upgrade in output power
Beam geometry & intensity distribution readily adapted
Diode laser stack(or SE module)
Polarisation coupling
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Laser diodes
µ-OpticsWavelength coupling
Laser Lines Ltd
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Beam Quality TrendsBeam Quality Trends
Fiber DiameterFiber Diameter150 mm mrad
100 mm mrad
60 mm mrad
40 mm mrad
30 mm mradLas
er p
ow
er [
W]
5Laser Lines Ltd
Diode Applications since 1999
1000
mra
d]
Market Movement Market Movement forfor Diode LasersDiode Lasers
Diode Applications since 2002
Diode Applications since 2004
10
100
10 100 1000 10000
Diode Applications since 2007
Cutting
Bea
m q
ua
lity
[m
m m
6Laser Lines Ltd
Diode Applications2009
Laser power [W]
Future ApplicationsDiode laser systems 2007
Diode laser systems 2009
Limits in Power and Beam quality
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4,000 W diode laser with a beam quality of 30 mm mrad (comparable with lamp pumped YAG)
Current top end specificationsCurrent top end specifications
)
Diode laser with 10,000 W laser power at the end of a 1mm fiber (100mm mrad)
2,300 W diode laser the size of an industrial PC
Compact packaging: 10,000 W in less than a
7Laser Lines Ltd
square meter footprint
5 year warranty on diode laser elements
Excellent Beam Quality and PowerExcellent Beam Quality and Power
specification
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p
max. output power 2,000 W 3,000 W 4,000 W 5,000 W
beam quality 20 mm∙mrad 30 mm∙mrad 40 mm∙mrad
laser light cable 400 µm, NA 0.1 300 µm, NA 0.2 or 600 µm, NA 0.1 400 µm, NA 0.2
min. spot at f = 100 mm 0.2 mm 0.3 mm 0.4 mm
power consumption, max. 7.5 kW 10 kW 13 kW 17 kW
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Control system upgrade
Profibus, Interbus, Device Net, Profi Net, Ethernet connection
Typical system options
Visible pilot laser
Up to 6 fibre outputs and time-share
Typical System OptionsTypical System Options
PC control: LL Control Software
Separate control panel
Teleservice via safe VPN connection
Wavelength stabilization for pump applications
Extended programming and
p pbeam switch
Cover slide cassette
Fiber length up to 100 m
Application specific optics
Closed loop pyrometer control
Dust and humidity protection
9Laser Lines Ltd
Extended programming and interaction functionalityGalvanometer scan heads
Easy integration in systems for production. Ease of use and service.
Modular optics for flexible adaptation to any process
R b t d i f hi h
OpticsOptics
Robust design for high power processes
Straightforward solutions for complex tasks
Customer specific focus geometries for almost every requirement
Optics for welding, brazing and cladding
Compatible with industrial standards
10Laser Lines Ltd
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Specialty SpotsSpecialty Spots
11Laser Lines Ltd
System integrationSystem integration
The fibre coupled diode laser is simple to integrate and is particularly suited to robotic applications.
12Laser Lines Ltd
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ApplicationsApplications: Spot : Spot RequirementsRequirements
Rectangular spot: 3 x 3 – 10 x 60 mm
1000
mra
d]
Spot: 1.5 – 3.5 mm
Spot: 0.3 – 0.8 mm
Spot: 0.6 - 3 mm
Spot: 0 2 – 0 6 mm
Spot: 1 - 6 mm
10
100
10 100 1000 10000
Be
am
qu
alit
y [m
m m
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Spot: 0.6 - 2 mm Spot: 0.5 - 5 mm
Spot: 0.2 – 0.6 mmLaser power [W]
Diode Laser can meet most of the spot requirements
Laser Lines Ltd
Heat Conduction Welding: steelHeat Conduction Welding: steel
Diode lasers are used in various application areas of mass production
Heat conduction welding of stainless steel sinks
Welding of bellows
Welding of battery housings
Tube welding
14Laser Lines Ltd
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Absorption of laser radiation: AlAbsorption of laser radiation: Al
High absorption peak of aluminum t 800 900at 800 – 900 nm
Degree of absorption A [%]:Nd:YAG => 5%Diode => 14%
15Laser Lines Ltd
Source: Audi, C.Ebert EALA 2009
Brazing Brazing
Related process of welding with filler wire
For requirements of high strengths and small heat affected zone
Photo: Irepa
High demands on appearance of the weld, visible weld
Main products at car body: roof seams, trunk lids, doors, C-pillars, water channels
16Laser Lines Ltd
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Laser Price & Beam Quality (joining)Laser Price & Beam Quality (joining)
Laser Price
Aluminium& Steel
Remotewelding
welding
Brazing
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Beam quality [mm mrad]
8-12 25-40 60-150
Beam quality should only be as good as required
Laser Lines Ltd
Laser Price & Beam Quality (joining)Laser Price & Beam Quality (joining)
Laser Price
Aluminium& Steel
Disc /Fiber Laser
∆ = 15 - 20 %
Remotewelding
welding
BrazingDiode Laser 30 mm mrad
∆ = 25 - 35 %
Diode Laser 100 mm mrad
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Beam quality [mm mrad]
8-12 25-40 60-150
Beam quality should only be as good as required
Laser Lines Ltd
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Cladding and Coating : PrincipleCladding and Coating : Principle
Laser Beam
Powder and assist gas is fed into the laser beam
coaxially or off-axis
Powdernozzle
and gas
Laser Beam melts powder and eventually base
material
Alloying or depositing of powder onto base
material in one or more layers
Repair or coating in a single process
Spot geometry adapted to parts and process
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Cladding zone
Spot geometry adapted to parts and process
Laser Lines Ltd
Cladding Installation with Diode Laser Cladding Installation with Diode Laser
Cladding/Coating with Diode laser
High precision thick deposits (0.5 – 4 mm)
Cladding rates of 9kg/hour have beenachieved with a 6kW laser
Fully automated, industrial process
Repair of valuable parts
Wear protection
Successful replacement of CO2 laser
Applications
Oil drilling – down hole tools
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Photo: Technogenia/Laser Cladding Technology Ltd
Laser Lines Ltd
Aerospace and maritime industries
Foundries – pan scrapers
Steel industry – conveyor rollers in steel mills
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Hardening: Typical DataHardening: Typical Data
Fiber-coupled or direct diode laser 1-6 kW
Rectangular spot, may vary by applications
First industrial installations in 1999First industrial installations in 1999
Pyrometer typically used for closed-loop process
control
Homogenized focus24 x 8 mm
21Photo: Erlas
Laser Lines Ltd
20 mm
Polymer Welding Polymer Welding
Transmission welding of thermoplastics
Contour welding on robot for even huge 3d-parts
Quasi-simultaneous weldingQuasi-simultaneous welding
Welding with base material strength
Main products: sensor housing, tubes, flat parts, leak/gas-proof containers, head/tail lights of cars
Special wavelengths possible. Eg. 14xx nm for welding of clear/clear acrylic
22Laser Lines Ltd
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High electrical/optical efficiency of more than 40 percent
Low investment and maintenance costs
ConclusionConclusion
Low investment and maintenance costs
Outstanding reliability and robustness (up time > 99 %)
Mobility and compactness
Easy integration in systems for production. Ease of use and service
Excellent beam quality
L i t d i (0 5 d )
23Laser Lines Ltd
Low maintenance design (0.5 day per year)
Excellent process stability and reproducibility
Thank you for your attention
Gary BroadheadLaser Lines Ltd
24Laser Lines Ltd