Role of CO2 laser cutting conditions on anisotropic properties of nanocomposite contain carbon nanotubes

This study attempts to investigate different CO2 laser conditions on electrical conductivity and surface properties of multiwalled carbon nanotubes/poly methyl methacrylate (MWCNT/PMMA) nanocomposite. In order to reach this aim, outputs like morphology of surface, electrical conductivity of laser cut surface, heat affected zone (HAZ), burr, and surface roughness were studied. The nanocomposite, which contains carbon nanotubes, exhibits anisotropic behavior, therefore, the laser cutting outputs are investigated within the in-flow direction and perpendicular to the flow direction. Morphology of the nanocomposites and cut surfaces are investigated using scanning electron microscopy that showed the contacts between nanotubes are increased after laser cutting. Findings obviously show increasing the laser power and decreasing the feed rate improve the electrical conductivity. As a prominent result, the minimum surface electrical resistivity was obtained from over 2 × 1014 to 886 Ω by using a power of 120 W, a cutting velocity of 0.3 m/min for 1.5 wt. % MWCNT into PMMA matrix. In the case of laser cutting outputs, the presence of MWCNTs increased HAZ, surface roughness in two directions, and burr in perpendicular to flow direction, but it decreases the burr in the in-flow directions. By increasing the cutting velocity, HAZ and burr decrease in two studied directions, but it has partial effect on surface roughness.