Experimental determination of temperature threshold for melt surface deformation during laser interaction on iron at atmospheric pressure
TypeArticles dans des revues avec comité de lecture
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 or to carry out numerical simulations. However, there exists no quantitative estimation of the recoil pressure near the boiling temperature (Tv), which is particularly important in welding process. In this study we experimentally investigated the recoil pressure of pure iron around Tv. The main interest was to determine the threshold surface temperature to start deformation of melt surface. Using camera-based temperature measurement with accurate evaluation of emissivity from experiment, it was shown that the surface temperature has to reach Tv to initiate the melt surface deformation. This result provides the first experimental evidence for the frequently used assumption that a deep keyhole welding requires surface temperature over Tv. It is indicated also that, in normal gas-assisted laser cutting process, the recoil pressure hardly contributes to material ejection when the surface temperature is lower than Tv, as opposed to commonly believed presumption.
Fichier(s) constituant cette publication
Cette publication figure dans le(s) laboratoire(s) suivant(s)
Visualiser des documents liés par titre, auteur, créateur et sujet.
Mesure de température par pyrométrie 2D à bande spectrale et pyrométrie spectrale de métaux chauffés par laser dans un environnement fortement oxydant MULLER, Maryse; FABBRO, Rémy; EL-RABII, Hazem; HIRANO, Koji (Société Française de Thermique / Congrès Français de Thermique - Thermique en conditions extrêmes, 29 mai - 1er juin 2012, Bordeaux, 2012)La calibration et la validation de deux techniques de mesure de température complémentaires basées toutes les deux sur la pyrométrie optique (pyrométrie 2D monobande et pyrométrie spectrale), utilisables dans le cadre de ...
Temperature measurement of laser heated metals in highly oxidizing environment using 2D single-band and spectral pyrometry MULLER, 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 ...
Analysis of the physical processes occurring during deep penetration laser welding under reduced pressure FABBRO, Rémy; HIRANO, Koji; PANG, Shengyong (2016)Recent published experimental results obtained on deep penetration laser welding realized under reduced ambient pressure have shown very interesting results: resulting weld seams have geometrical characteristics that are ...
PANG, 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 ...
Possible explanations for different surface quality in laser cutting with 1 micron and 10 microns beams HIRANO, Koji; FABBRO, Rémy (AIP, 2012)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 ...