Laser processing of carbon black reinforced ethylene-butyl acrylate copolymer

Interest in the phenomenon of laser ablation (LA) has gained significant attention in recent years due to its potential for machining, high-precision drilling, and cutting materials, such as metals, semiconductors, and dielectrics. Here, LA of ethylene-butyl acrylate (EBA) filled with different volume fractions (4%, 8%, and 20%) of CB particles is studied. Upon irradiation with the second harmonics (532 nm) of the nanosecond pulsed Nd:YAG laser, a structuration is evidenced at the sample surface in a restricted range of fluence and at high pulse number (PN) (500 pulses, 1 Hz). The laser-ablated surface is analyzed by microtopography, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy (XPS). Collectively, our data show a lowering in ablation threshold and depth for CB volume fractions larger than the conduction threshold (8%), indicating that visible radiation primarily induces photothermal effects. After redeposition of the ablation products at the surface, XPS indicates that high CB content in the EBA matrix induces high oxidation level of the composite surface. Furthermore, our results reveal that LA produces a significant proportion of amorphous carbon. Several parameters which affect heat accumulation and CB particle shielding are discussed. Such parameters include laser fluence and repetition rate, and CB content.