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#12048 High Power Laser materials processing - Cutting and Welding of various metals

Ewa Ziolkowski, Susanna Friedel, Klaus Stolberg, ALAB – LT Jenoptik Laser GmbH Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz


Cutting Welding Workflow Literature research

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz


Task description “Cutting”

Sample: •Stainless steel (1.4301)1.0mm and 2.0mm •Aluminum (AlMg3) 1.0mm •Copper 1.0mm Quality requirements: •No burr •Smooth cutting edge (small surface roughness) •as fast as possible

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 3


Summary

It is possible to cut stainless steel up to 2.0mm and aluminum up to 1.0mm with a sound cutting speed with the JenLas速fiber cw 1000 (Prototype) SM. Due to high reflectivity it was not possible to cut through copper 1.0mm. Other material thicknesses have not been tested yet. Highest possible cutting speed was 18m/min for 1.0mm steel, higher speed could not be evaluated due to end of movement speed of x-y-stage. Further evaluation have to be done for surface roughness .

There have not been any tests for aluminum and steel sheets thinner than 1.0mm due to limit of equipment (x-y-stage)!

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 4


Laser JenLas®fiber cw 1000 SM

Laser:

JenLas®fiber cw 1000 SM (Prototyp)

Specification: wavelength: pulse length: repetition rate: power M2

1070nm cw or modulated cw… 5kHz 1000W <=1.2

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 5


Optical setup for cutting

Beam delivery:

cutting head

Processing optics: fixed optics

F120 K 125 leads to spot size of about 20µm

Side remarks: •processing gas (N2) with 3 different nozzels (diameter 1.0mm, 1.2mm and 1.5mm) •processing gas pressure: 16bar •exhaust for ablation products •All trials are done with non movable cutting head, movement of samples is done by a x-y-stage (maximum movement speed 18m/min) Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 6


Overview of Cutting results with 1kW

Material and thickness

Nozzel size [mm]

Best Cutting Speed )* [m/min]

Focal position [mm]

Quality

Stainless steel 1.0mm

1.0

18

-1

Good

Stainless steel 1.0 mm

1.2

5

0

Burr

Stainless steel 2.0mm

1.2

5

-2

Good

Stainless steel 2.0mm

1.2

5

-1

Burr

Stainless steel 2.0mm

1.5

6

-1

Burr

Stainless steel 2.0mm

1.5

5

-2

Nearly no burr

Aluminium 1.0mm

1.2

18

0

Burr

Aluminium 1.0mm

1.2

16

-1

Good

Aluminium 1.0mm

1.0

18

0

Good

)* Remark: 18m/min is maximum moving speed of x-y-Stage, another equipment may lead to higher cutting speeds

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Overview of Cutting results 0.5kW

Material and thickness

Nozzel size [mm]

Best Cutting Speed )* [m/min]

Focal position [mm]

Quality

Stainless steel 1.0mm

1.2

10.0

-1

Burr)**

Stainless steel 1.0 mm

1.0

9.0

-1

Good

Stainless steel 1.0mm

1.0

8.0

0

Burr

Stainless steel 1.0mm

1.2

9.0

0

Burr

Stainless steel 2.0mm

1.2

3.0

0

Burr

Stainless steel 2.0mm

1.2

2.1

-2

Burr

Stainless steel 2.0mm

1.5

2.0

-2

Good

Aluminium 1.0mm

1.2

6.0

-1

Nearly no burr

Aluminium 1.0mm

1.0

7.0

-1

Burr

)* Remark: 18m/min is maximum moving speed of x-y-Stage, another equipment may lead to higher cutting speeds )** no burr at 9m/min!

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Detail photographs of cutting edges - Aluminum 1.0mm Best quality

Highest cutting speed

v= 5.25m/min; no burr, smooth cutting edge

v=16m/min; burr, edges are not as smooth as with v=5.25m/min

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Detail photographs of cutting edges - Steel 1.0 mm Highest cutting speed for steel plate

v= 18m/min No burr, smooth cutting edge

Highest cutting speed for aluminum plate

v=16m/min; burr, edges are not as smooth as for steel plate 1.0 mm

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Detail photographs of cutting edges - Steel 2.0 mm

Highest cutting speed

v=5m/min no burr, higher roughness as for steel 1.0mm

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Results of cutting various metals

Material and thickness

Best cutting speed )* [m/min]

Cutting speed with best quality [m/min]

Stainless steel 1.0mm

18.0

18.0

Stainless steel 2.0 mm

6.0

5.0

Aluminum 1.0mm

18

18

)* Remark: 18m/min is maximum moving speed of x-y-Stage, another equipment may lead to higher cutting speeds

Aluminum and steel with a thickness of 1.0mm achieve the same cutting speed results. For aluminum there was more burr, grooves seam to be more curved and edges are not as smooth as for steel.

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 12


Cutting Welding Workflow Literature research

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 13


Task description “Welding”

Sample: •Aluminum 1.0mm (lap joint) •Aluminum 5.0mm (blind welding)

Quality requirements: •smooth weld seam •no discoloration •no porosities •no cracks

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 14


Summary

It is possible to weld aluminum with JenLas速 fiber cw 1000 (Prototype) SM. Welding depth was measured in varying the welding speed. A weld seam can be detected up to 13.5m/min. Maximum weld depth (2.6mm) was measured at minimum used welding speed at 1.2m/min.

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 15


Optical setup for welding

Beam delivery:

laser processing head

Processing optics: fixed optics

F200 K 310 leads to a spot diameter of about 30µm

Side remarks: •processing gas (N2) with a pressure of 3 bar •reduced positioning accuracy due to usage of 6-axis-robot

Authorized distributor and Application specialist for Czech Republic LINTECH, spol.s r.o. www.lintech.cz 16


Overview of Welding Results Welding depth at different welding speeds

1400

2800

1200

2400

1000

2000

800

1600

600

1200

400

800

200

400

0 0,0

2,0

4,0

6,0

8,0

10,0

12,0

weld depth [Âľm]

Seam width [Âľm]

Welding Seam geometry

0 14,0

welding speed [m/min]

Maximum welding depth is 2.6mm, maximum welding width is 1.2 mm both measured at minimum used welding speed of 1.2m/min. Depth and width scale with higher welding speeds. At maximum possible welding speed, depth was 1.2mm and width 0.4mm 17


Detail photographs of welding depths and widths - variation of welding speed

0.4mm

1.2mm

1.2mm 2.6mm

v=13.5m/min; smooth welding seam without porosities and cracks; very small reinforcement of welding seam, aspect ratio 1:3; nail-head-shaped welding seam

SAME MAGNIFICATION (5x)!

v=1.2m/min, smooth welding seam without porosities and cracks, reinforcement comparable to that at 13.5m/min aspect ratio ~1: 2 ;v-notch welding seam 18


Detail photograph of welding depths and widths - variation of focal position -z v=4.8m/min; focal position: -2mm; small reinforcement; no other irregularities

z=0 +z

v=4.8m/min; focal position: +2mm; weld seam is collapsed at the top of sample, no other irregularities

welding depth

Maximum welding depth was detected for z=-2.0mm!

seam depth [Âľm]

2400 2000 1600 1200 800 400 0 -4,0

-3,0

-2,0

-1,0

0,0

1,0

2,0

focal position z [mm]

19


Outlook

Proposal of next steps: Further cutting trials with titanium (0.5mm; 1.0mm), aluminum (2.0mm) and copper (0.5mm). Further welding trials for titanium (0.5mm; 1.0mm – lap joint and blind welding – ) and stainless steel (1.0mm – lap joint – ).

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Cutting Welding Workflow Literature research

21


Workflow for cutting trials

1. Setting of cutting head and x-y-stage a.

cutting head have to be fixed onto the x-y-stage and have to be loaded up into the x-y-stage control system

b.

x-y-stage and carriage for sample have to be reset for further steps

c.

cooling and fiber have to be adjusted to the cutting head

d.

cooling for JenLasÂŽ fiber cw 1000 (prototype) and laser itself have to be adjusted

e.

cutting process gas have to be installed If nothing is prepared this will take about 3 hours.

2. Setting of focal position 3. Adjustment of sample 4. Execution of trials

2. â&#x20AC;&#x201C; 5. can take up to 3 hours for one material in one thickness

5. Collection of trial data 6. Post processing and evaluation Duration depends on requirements of customer and type of application. Can take about 4 hours up to 5 hours. 22


Workflow for welding trials

1.

Setting of cutting head and x-y-stage a.

cutting head have to be fixed onto the robot and have to be loaded up into the robot control system

b.

robot has to be reset for further steps

c.

cooling and fiber have to be adjusted to the processing head

d.

cooling for JenLas速 fiber cw 1000 (prototype) and laser itself have to be adjusted

e.

protection gas have to be installed

If nothing is prepared this will take about 3 hours. 2.

Setting of focal position

3.

Adjustment of sample

4.

Execution of trials

5.

Collection of trial data

6.

Post processing and evaluation Duration depends on requirements of customer and type of application. Can take about 6 hours up to 10 hours.

Similar to Workflow of cutting trials BUT post processing takes much more time!!! 23


Workflow of post processing of welding trials

1. Grinding and polishing of samples a.

All samples are ground in several steps; grain size became smaller with every steps. Depending on requirements of customer and type of application the samples also have to be polished.

b.

after each grinding and polishing step the sample and the grinding machine (for polishing also the polishing disc) have to be cleaned with water carefully.

2. Etching a.

For each material there is a special etching agent. For stainless steel (1.4301) Adler etching agent was used (contains hydrochloric acid), for aluminum Keller etching agent or sodium hydroxide solution was used

b.

Success of Etching always depends on residence time.

3. Microscopy

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Cutting Welding Workflow Literature research

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Literature research “ Cutting with 1kW fiber laser SM”

IWS Dresden

Jenoptik Laser GmbH (Mai-Jul. 2012)

IPG 1kW SM fiber laser

JenLas® fiber cw 1000 (prototype) SM

Material and thickness

Highest cutting speed [m/min]

Spot size [µm]

Material and thickness

Best cutting speed )* [m/min]

Spot size [µm]

Stainless steel 1.0mm

~24m/min

10

Stainless steel 1.0mm

18.0

20

Stainless steel 2.0 mm

~11m/min

10

Stainless steel 2.0 mm

6.0

20

St1203 1.0mm

15m/min

15

Aluminum AlMg31.0mm

18

20

Aluminum AlMg3 1.0mm

16m/min

15

)* Remark: 18m/min is maximum moving speed of x-y-stage, another equipment may lead to higher cutting speeds

26


Literature research “ Welding with 1kW fiber Laser SM”

IWS Dresden, BIAS Bremen

Jenoptik Laser GmbH (Jul. 2012)

IGP 1kW SM fiber laser – blind welding

JenLas® fiber cw 1000 (prototype) SM – blind welding

Material and thickness

Welding speed [m/min]

Weld depth [mm]

Spot size [µm]

Material and thickness

Welding speed [m/min]

Weld depth [mm]

Spot size [µm]

Stainless steel (IWS)

1.0

2.4

180

Aluminum AlMg3

1.2

2.6

30

Stainless steel (IWS)

7.5

1.4

180

Stainless steel (BIAS)

10

2.5

20

Aluminum AlMg3 (IWS)

1

2.6

35

Aluminum AlMg3 (IWS)

2

2.4

35

Aluminum AlMg3 (IWS)

10

1.8

35

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High power laser cutting welding