R.L. Vander Wal, J. Abrahamson
Penn State University,
Keywords: laser, carbon, annealing, graphitization, TEM
Summary:Laser processing of materials is not new, but, using lasers to anneal, bond and otherwise transform carbons is. Fundamental understanding of the dependence upon carbon structure, morphology and chemistry is critical to implementing this technology into manufacturing and processing applications. In this work a Q-switched Nd:YAG laser and a continuous wave CO2 laser are used to anneal anthracene coke and sucrose char. Anthracene coke and sucrose char were selected for laser annealing because they represent a model graphitizable and non-graphitizable carbon, respectively. Lasers provide rapid heating and cooling with high temporal control. The extent of transformation is kinetically controlled by time above the threshold temperature for transformation. Enabling the annealing trajectories from these two very different carbon materials to be followed with respect to time above temperature. To resolve the nanostructure changes HRTEM is employed. Results are compared with RexaxFF, as shown in Fig. 1.