Lernkarten
Wich two types of laser welding exist?
- Deep-penetration laser-welding
- Heat-conduction laser-welding
Explain how deep-penetration-welding works.
• Vaporization-temperature of the workpiece is exceeded due to high laserpower and good focussing (small df), which leads to high intensity.
• Metal-vapour streams vertically up, the resulting recoil (Rückstoß) onto the liquid melt-pool-surface causes the creation of a deep and narrow vapourchannel (D„ ampfkapillare)“, often called a „keyhole)“.
• Through the keyhole (D„ ampfkapillare)“ the laser-beam enters the workpiece into deep depths and such warms it up „from the inner“(and not only „from the surface)“.
Explain the "multi-reflections-effect" during deep-penetration-welding.
Wich ammount of energy can be absorbed using a high sophisticated process?
During the multiple reflections of the laser-beam inside the keyhole (Dampfkapillare) every time a ray (Teilstrahl) touches the keyhole-walls, an amount of it´s energy is absorbed there.
Touching the keyhole-walls sufficiently frequent, the total amount of absorption in practice can reach high numbers of up to > 90%.
How does a typical setup of a laser welduing optic look like?
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Wich laser suits for the follwowing application(s)?
Delicate (filigran) components, with only low allowed thermal stresses (wenig wärmebelastbar), e.g. microtechnology
(1) pulsed YAGlasers; (2) cwYAG-lasers (with low PL); (3) Diode lasers
YAG with LLK
Pulsed YAGlaser, preferably without LLKs (fibre-cables)
CO2-laser
Wich laser suits for the follwowing application(s)?
Thin walled (dünnwandig) components ( < ca. 0,4 mm )
Pulsed YAGlaser, preferably without LLKs (fibre-cables)
YAG with LLK
YAG-lasers, with or without LLK
(1) pulsed YAGlasers; (2) cwYAG-lasers (with low PL); (3) Diode lasers
CO2-laser
Wich laser suits for the follwowing application(s)?
3D-Welding-Paths
YAG with LLK
Pulsed YAGlaser, preferably without LLKs (fibre-cables)
CO2-laser
YAG-lasers, with or without LLK
(1) pulsed YAGlasers; (2) cwYAG-lasers (with low PL); (3) Diode lasers
Wich laser suits for the follwowing application(s)?
Non ferrous (NE-) metals with high reflectivity (e.g. Al, Cu)
(1) pulsed YAGlasers; (2) cwYAG-lasers (with low PL); (3) Diode lasers
YAG-lasers, with or without LLK
CO2-laser
Pulsed YAGlaser, preferably without LLKs (fibre-cables)
YAG with LLK
