Abstract:
The quality of the joints produced by means of Laser-Assisted Metal to Polymer direct joining (LAMP) is
strongly influenced by the temperature field produced during the laser treatment. The main phenomena
including the adhesion of the plastic to the metal sheet and the development of bubbles (on the plastic
surface) depend on the temperature reached by the polymer at the interface. Such a temperature should
be higher than the softening temperature, but lower than the degradation temperature of the polymer.
However, the temperature distribution is difficult to be measured by experimental tests since the most
polymers (which are transparent to the laser radiation) are often opaque to the infrared wavelength.
Thus, infrared analysis involving pyrometers and infrared camera is not suitable for this purpose. On
the other hand, thermocouples are difficult to be placed at the interface without influencing the temperature conditions. In this paper, an integrated approach involving both experimental measurements and a
Finite Element (FE) model were used to perform such an analysis. LAMP of Polycarbonate and AISI304
stainless steel was performed by means of high power diode laser and the main process parameters
i.e. laser power and scanning speed were varied. Comparing the experimental measurements and the
FE model prediction of the thermal field, a good correspondence was achieved proving the suitability
of the developed model and the proposed calibration procedure to be ready used for process design
and optimization.
