Influence of the laser cutting front geometry on the striation formation analysed with high-speed synchrotron X-ray imaging
Open Access
- 1 November 2021
- journal article
- Published by IOP Publishing in IOP Conference Series: Materials Science and Engineering
- Vol. 1135 (1)
- https://doi.org/10.1088/1757-899x/1135/1/012009
Abstract
The generation of low surface roughness of the cut edge during laser beam cutting is a challenge. The striation pattern, which determines the surface roughness, can be distinguished into regular and interrupted striations, the latter resulting in an increased surface roughness. In order to analyse their formation, the space- and time-resolved cutting front geometry and melt film thickness were captured during laser beam fusion cutting of aluminium sheets with a framerate of 1000 Hz by means of high-speed synchrotron X-ray imaging. The comparison of the contours of the cutting fronts for a cut result with regular und interrupted striations shows that the contour fluctuates significantly more in case of interrupted striations. This leads to a strong fluctuation of the local angle of incidence. In addition, the average angle of incidence decreases, which results in an increase of the average absorbed irradiance. Both phenomena, local increase of absorbed irradiance and its dynamic fluctuation, result in a local increase of the melt film thickness at the cutting front which is responsible for the formation of the interrupted striations.This publication has 18 references indexed in Scilit:
- Keyhole threshold and morphology in laser melting revealed by ultrahigh-speed x-ray imagingScience, 2019
- In-situ high-speed X-ray imaging of piezo-driven directed energy deposition additive manufacturingScientific Reports, 2019
- Influence of the Real Geometry of the Laser Cut Front on the Absorbed Intensity and the Gas FlowLasers in Manufacturing and Materials Processing, 2018
- Dynamics of solid-liquid interface and porosity formation determined through x-ray phase-contrast in laser welding of pure AlJournal of the American Academy of Dermatology, 2017
- Real-time observation of laser cutting fronts by X-ray transmissionJournal of the American Academy of Dermatology, 2016
- Local flashing events at the keyhole front in laser weldingOptics and Lasers in Engineering, 2015
- The High Energy Materials Science Beamline (HEMS) at PETRA IIIMaterials Science Forum, 2013
- Space-resolved Spectrometric Measurements of the Cutting FrontPhysics Procedia, 2011
- Experimental investigation of hydrodynamics of melt layer during laser cutting of steelJournal of Physics D: Applied Physics, 2011
- Inert gas cutting of thick-section stainless steel and medium-section aluminum using a high power fiber laserJournal of Laser Applications, 2009