Abstract
Over the past few years there has been an enormous increase in the
use of tailored blanks, especially in the automotive industry.
Often the sheets for tailored blanks are shear cut, but results
have been reported that the allowable sheet gap distance should
not exceed 0.1 mm in order to obtain sound welds. Laser cutting
the sheets may therefore be an alternative to shear cutting, if
the cut kerf squareness can be kept below 0.05 mm.In a number of
systematic laboratory experiments the effects of the major process
parameters in laser cutting have been investigated. Each cut was
quantified by the squareness, the surface roughness and the burr
height. Mild steel as well as high strength steel with and with
out galvanisation with thickness' of 0.7(5) and 1.25 were used.In
the tests the difference in cut quality between a 5" and a 7.5"
focusing lens were tested and the effect of using pulsed mode
laser cutting instead of continuous wave cutting at average power
settings of approximately 500, 1000, 1500 and 2000 W were
analysed. Furthermore the optimum assist gas pressure and optimum
cutting speeds were identified. The results showed that the
highest qualities are obtained with a 7.5" focusing lens.
Generally pulsed mode cutting give the best overall cut quality
and result in the highest cut speeds as compared to cw mode
cutting. The best cuts are obtained at an average power of 2000 W
and a pulse energy of 1.42 J.Seven out of eight materials were cut
with high quality with a squareness between 0.01 mm and 0.05 mm at
optimum. All 1.25 mm sheets have been cut with high qualities
(except galvanised mild steel) at speeds of about 8 m/min. whereas
sheets of 0.7(5) mm thickness have been cut with high qualities
between 12 and 17 m/min.
Original language | English |
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Title of host publication | 7th NOLAMP CONFERENCE, Nordic conference in Laser Processing of Materials |
Place of Publication | Lappeenranta |
Publisher | Acta Universitatis Lappeenrantaensis |
Publication date | 1999 |
Pages | 297-306 |
Publication status | Published - 1999 |
Event | 7th NOLAMP, Nordic conference in Laser Processing of
Materials - Lappeenrannta Duration: 1 Jan 1999 → … |
Conference
Conference | 7th NOLAMP, Nordic conference in Laser Processing of Materials |
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City | Lappeenrannta |
Period | 01/01/1999 → … |