Measurement of plasma and shock-wave dynamics and properties inside holes during laser drilling of metals

Publikationstyp
Conference Paper
Date Issued
2008-10
Sprache
English
Author(s)
Brajdic, Mihael  
Hermans, Martin  
Kaminsky, Michel  
Kelbassa, Ingomar  
TORE-URI
http://hdl.handle.net/11420/12511
Start Page
37
End Page
42
Citation
ICALEO 2008 - 27th International Congress on Applications of Lasers and Electro-Optics, Congress Proceedings: 37-42 (2008)
Contribution to Conference
27th International Congress on Applications of Lasers and Electro-Optics, ICALEO 2008  
Publisher DOI
10.2351/1.5061350
Scopus ID
2-s2.0-75149124694
Publisher
Laser Inst. of America
ISBN of container
978-0-912035-12-3
Laser material processing can be influenced by plasma formation and dynamics such as plasma shielding or plasma supported ablation. A novel method for investigating in-situ plasma and shock-wave dynamics inside a confined space like a laser drilled hole in metals is presented. A specific sample preparation with prepared mock-up holes including a transparent material as a window is used. By use of high speed imaging and spectroscopy a time and spatially resolved monitoring of the optical emissions of plasma and shock-waves is realized during drilling stainless steel and aluminum with ns-pulsed laser radiation. Spatial intensity distributions and velocities of the shockwaves and the plasma are measured inside the holes with a temporal resolution of 1 ns and a spatial resolution of less than 1 μm. The results are compared with models for shock-wave and plasma propagation in non-confined environments. Emission spectroscopy is carried out during the expansion of the plasma inside the drilled hole allowing the determination of electron density by Stark broadening.
DDC Class
530: Physik