“Laser welding of polymers and hybrid laser joining of polymer-metal”

This article presents the study of laser transmission welding of polymeric joints that are composed of two ABS (Acrylonitrile/Butadiene/Styrene) sheets, one transparent and the other absorbent to the laser radiation. 

The latter is formulated with different percentages of carbon nanotubes (CNTs). The objective of this research is to analyze the effect of laser process parameters and CNTs concentrations on weld formation and mechanical resistance of the joints.

Thermal and optical characterizations of transparent and doped ABS sheets are studied. Microscopic characterization of joints and mechanical shear test of the joint were carried out. The results concerning weld formation and mechanical properties suggest a high sensitivity of the doped ABS with high concentration of CNTs to specific changes in the incident laser intensity. This sensitivity changes could be related with the changes in the optical properties of the doped polymer.

A step forward and related to this previous investigation will be materialized in the recently approved PMjoin project (FP7-NMP-2012-SMALL-6 GA 309993) which will use in some cases the same concept of laser transmission welding for the joining of laser transparent polymers with metals or conductive methodology for the joining of laser opaque polymers with metals. Metal surface modifications will be considered to improve the interconnection between these dissimilar materials.