NUMERICAL AND EXPERIMENTAL ANALYSIS OF CONVECTION TRANSFER DURING MELTING BY A MONO-PULSED LASER

摘要

This paper presents a comparison between simulation and experimental results of the melting process of metallic material by a pulsed laser source Nd-YAG. Variations of the thermophysical properties were considered. Furthermore, the model included the effects of the surface-tension gradient on the fluid. surface and the buoyancy force. The keyhole effect induced strong surface deformations and often formed cavities, which arre undesirable in the surface treatment process. An experimental study of the surface profile of the melted zones was also conducted to seek a relationship between the so-called keyhole effect and the laser triangulation measurements. The predicted Laser Melted Zone (LMZ) morphology was in good agreement with the corresponding experimental measurements for various irradiation conditions, as long as the keyhole effect did not occur.