Possible explanations for different surface quality in laser cutting with 1 micron and 10 microns beams
Article dans une revue avec comité de lecture
In laser cutting of thick steel sheets, quality difference is observed between cut surfaces obtained with 1 micron and 10 micron laser beams. This paper investigates physical mechanisms for this interesting and important problem of the wavelength dependence. First, striation generation process is described, based on a 3D structure of melt flow on a kerf front, which was revealed for the first time by our recent experimental observations. Two fundamental processes are suggested to explain the difference in the cut surface quality: destabilization of the melt flow in the central part of the kerf front and downward displacement of discrete melt accumulations along the side parts of the front. Then each of the processes is analyzed using a simplified analytical model. The results show that in both processes, different angular dependence of the absorptivity of the laser beam can result in the quality difference. Finally we propose use of radial polarization to improve the quality with the 1 micron wavelength.
Files in this item
Showing items related by title, author, creator and subject.
Article dans une revue avec comité de lecturePANG, Shengyong; HIRANO, Koji; FABBRO, Rémy; JIANG, Tao (Laser Institute of America, 2015)It has been observed that the penetration depth during laser welding (LW) under vacuum or reduced ambient pressure could be significantly greater than that during welding under atmospheric pressure. Previous explanations ...
Experimental determination of temperature threshold for melt surface deformation during laser interaction on iron at atmospheric pressure Article dans une revue avec comité de lectureHIRANO, Koji; FABBRO, Rémy; MULLER, Maryse (IOP Publishing, 2011)Recoil pressure is the principal driving force of molten metal in laser processing in the intensity range of 10^-1 ~ 10^2 MW/cm2. It is thus essential to estimate the recoil pressure in order to describe physical processes ...
Temperature measurement of laser heated metals in highly oxidizing environment using 2D single-band and spectral pyrometry Article dans une revue avec comité de lectureMULLER, Maryse; FABBRO, Rémy; EL-RABII, Hazem; HIRANO, Koji (Laser Institute of America, 2012)Calibration and validation of two temperature measurement techniques both using optical pyrometry, usable in the framework of the study of the heated metals in highly oxidizing environments and more generally during laser ...
Article dans une revue avec comité de lectureAMARA, El Hachemi; KHELOUFI, K; TAMSAOUT, T; FABBRO, Rémy; HIRANO, Koji (Springer Verlag, 2015)A theoretical approach based on a numerical simulation using experimental data is proposed as a contribution for the study of laser metal cutting under gas assistance. The aim is to simulate the stages of the kerf formation ...
Article dans une revue avec comité de lectureHIRANO, Koji; FABBRO, Rémy (IOP Publishing, 2011)In laser cutting process, understanding of hydrodynamics of melt layer is significant, because it is an important factor which controls the final quality. In this work, we observed hydrodynamics of melt layer on kerf front ...