Sheet metal cutting with fiber lasers

Transcription

1 Sheet metal cutting with fiber lasers About Bystronic Introduction Results and Discussion Summary Andreas Lüdi and Stefan Wittwer Bystronic Laser AG

2 Bystronic: Key Figures Established in 1985 Field of activity: Sheet Metal Processing Systems Headquarters: arters Niederönz (CH) Since 1994 part of the Conzzeta Group Sales 500 mio. (2008) Employees , Folie 2

3 Bystronic: Core Activities iti Laser Waterjet t Cutting Cutting Bending Process chain: cutting - bending All from a single source For all flat materials and all shapes Handling & Software & Services & Automation Control Support Automation of the complete materials and data flow For increased productivity and cost efficiency , Folie 3

4 Introduction/Motivation ti ti ti Wish list for a laser cutting system Cost-effective e Reliable autonomous operation Energy-efficient efficient Compact layout Simple operation Little maintenance Continuous high output Good cut quality CO 2 fiber Source: PM By , Folie 4

5 Optic configurations f C d Fiber d Focus =(f F /f C ) d Fiber several optic configurations 450 f C [mm] f F diameter [u um] µm 100 µm focal µm 100 d Focus , Folie focal length f[mm] F

6 Cutting results 2005: Aluminum Aluminium Speed Vorschub (mm/min) Cuttin ng speed Fiber IPG 2 kw CO2 Bylaser kw CO2 Bylaser kw CO2 Bylaser kw CO2 Bylaser kw Thickness Dicke (mm)[mm] > 4mm similar to 2 kw CO 2 < 4mm faster than 5 kw CO 2 Quality Similar to CO , Folie 6

7 Cutting results 2005: Steel (O 2 ) Baustahl Speed Vorschub (mm/min) Cutting speed Fiber IPG 2 kw CO Bylaser kw CO Bylaser kw CO Bylaser kw CO Bylaser kw Thickness [mm] Dicke (mm) > 5mm similar to 2 kw CO 2 < 5mm similar to 5 kw CO 2 Quality < 6mm very good > 6mm good , Folie 7

8 Cutting results 2005: Stainless steel Vorschub b (mm/min) Cuttin ng speed Edelstahl Faserlaser IPG Fiber 2 kw Bylaser2200 CO 2 2 kw Bylaser4000 CO 2 4 kw Bylaser4400 CO kw Bylaser5200 CO 2 5 kw Thickness Dicke (mm) [mm] Speed > 4mm similar to 2 kw CO 2 < 4mm faster than 5 kw CO 2 Quality Rather rough cut, worse than CO , Folie 8

9 Cutting results 2005: Stainless steel fiber fiber laser: 4mm stainless steel rough cut; R z ~ 30 µm (lower region) R z <10 µm CO 2 laser: 4mm stainless steel smooth surface with R z < 10 µm CO , Folie 9

10 Cutting possibilities: Fiber vs. CO2 N2 Fiber laser cuts faster Comparable cut quality of fiber- and CO 2 -laser Good cut quality only with CO 2 -laser O2 Comparable cutting speed of CO 2 and fiber laser Comparable cutting quality of CO 2 and fiber laser 1mm - 5mm 5mm - 20mm , Folie 10 comparison with equal optical power / Source: Optech Consulting, 2009

11 Situation ti today Today, most fiber laser cutting machines are used for thin sheets. -ByVention Fiber 2 kw 2007 Munich (presented on Laser 2007 WORLD OF PHOTONICS, Munich) -several fiber laser cutting machines have been presented on Euroblech 08, Hannover , Folie 11

12 an approach to improve cut quality Laser beam a.u.] Absorption [a , Folie 12 Angle of incidence v [deg]

13 Angle of incidence id Laser beam Laser beam Laser beam D sheet v i = v min D sheet tan -1 ( ) D D Laser beam , Folie 13

14 Angle of incidence: id sheet thickness ] Absorption [a.u.] Angle of incidence v [deg] v i = v min D sheet tan -1 ( ) D D Laser beam , Folie 14

15 Angle of incidence: id beam tilting 85 Blechdicke=4mm, D sheet mm, Durchmesser D Laser =0.3 Strahl=0.4 mm mm wdeg] Angle Winkel v [d Winkel Angle a [deg] , Folie 15

16 Angle of incidence: id elongated beam U.] ption [a.u Absorp Angle of incidence v [deg] , Folie 16 v min = D tan -1 ( sheet ) D Laser beam

17 Angle of incidence: id focal position Extreme focal position U.] ption [a.u Absorp Angle of incidence v [deg] , Folie 17

18 Cut quality improvements Standard cut Cut with extreme focal position 26.1 µm 16.9 µm 47.3 µm 21.7 µm 70.2 µm 28.0 µm ; D=6 6mm Reduced burrs Reduced roughness , Folie 18

19 Summary - 1µm lasers have inherent disadvantage concerning fusion cutting of thick sheet metals (and v.v. concerning thin sheet metals) [a.u.] Absorption - Improvements of cut quality can be achieved by improved incoupling of laser radiation Angle of incidence v [deg] Thank you for your attention , Folie 19