Search: onr:"swepub:oai:DiVA.org:ltu-7457" >
Fresnel absorption ...
Fresnel absorption of 1 μm- and 10 μm-laser beams at the keyhole wall during laser beam welding : Comparison between smooth and wavy surfaces
-
- Kaplan, Alexander (author)
- Luleå tekniska universitet,Produkt- och produktionsutveckling
-
(creator_code:org_t)
- Elsevier BV, 2012
- 2012
- English.
-
In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 258:8, s. 3354-3363
- Related links:
-
https://urn.kb.se/re...
-
show more...
-
https://doi.org/10.1...
-
show less...
Abstract
Subject headings
Close
- The angle-dependent absorption of laser beams at metal surfaces is described by the Fresnel-equations. During keyhole laser welding the essential interaction takes place at very striping angles of incidence of the order of 1-8 degrees at the front of the vapour capillary, called the keyhole. For a smooth vapour capillary, laser beams with a wavelength of about 1 μm operate in a Fresnel-regime where the absorptance increases with the angle of incidence at the wall, towards the weak Brewster-angle maximum. In contrast, for 10 μm-lasers high absorptance around the more pronounced Brewster-angle peak takes place. From high speed imaging keyhole surface waves were observed. Mathematical modelling of the laser-keyhole interaction demonstrates that already relatively little waviness of the melt surface at the keyhole strongly modulates the angles of incidence and in turn the Fresnel-absorption due to varying angles of incidence, soon also leading to shadow zones. Due to this local variation of the angle of incidence the absorptance tends towards the angle-averaged value, with the consequence that for 1 μm-lasers the direct absorptance and in turn the penetration depth increases, particularly at low welding speed, while for 10 μm-lasers it generally decreases.
Subject headings
- TEKNIK OCH TEKNOLOGIER -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)
Keyword
- Produktionsutveckling
- Manufacturing Systems Engineering
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
To the university's database