materials, the combined effect of thickness and color and so on [2], but for modeling this attenuation all
the researchers are using the Beer-Lambert law [3, 4, 5] which is appropriate in the case of absorbent
polymers but not for low absorbent and scattering media. The scattering of the laser beam is an
important phenomenon because it has a great influence on the energy distribution within the materials,
especially at the interface where the heat source has to be defined. An experimental solution to this
necessity was given by Potente and Becker [6, 4] which measured the laser beam profile before and
after the transparent component thus obtaining both the attenuation and the energy distribution at the
interface. Within the present study the scattering of the laser beam in semitransparent low absorbent
polymers is modeled combining Mie theory and the Monte-Carlo method. This numerical model allows
a good estimation of laser beam profile at the polymers interface and therefore a well defined heat
source.
In computing the temperature field within the materials and at the interface the heat conduction
equation is used [3, 4, 5 ,6 ,7] taking in account a perfect contact between the two components
subjected to welding. An estimation of the temperature at the interface is required for establishing the
welding process parameters like laser power and welding speed. There are also studies that consider a
contact conduction between the joining components [3] based on the roughness of the surface, the
contact pressure and the elastic modulus of the materials, parameters that varies with temperature
during the welding process. In the present study, a hypothesis of a perfect contact between the two
components was considered due to a reduce thickness of the T leg (2mm) and the good quality of the
contact surface.
Within the frame of the present study, experimental and theoretical aspects of the laser welding
are combined in order to determine the weldability of natural and black pigmented ABS plates.
Experimental set-up and materials